Simulation and Gaming Software Development Tools and Languages

Software

This part of the EUROSIS website covers the free/open source software simulation and gaming development packages (or reasonably priced ones) which are out there. As the list grows this page will be split into 3 different pages. Feel free to suggest other software links here.


Bookmark and Share

Simulation and Modelling

3D Modelling

Abyssal Engine - The Abyssal Engine is a powerful professional game creation tool kit and rendering system for creating quality 3D software. The technology is designed to reduce development time while empowering developers with a strong suite of tools needed to produce great visual effects and immersive online or offline worlds. The technology allows the developer to create everything from single player RPG titles, Real Time Strategy Games, to Multiplayer and Massively multiplayer products as well as simulation applications. (The tool has a 30 day free trial period)
Cafu - The Cafu Engine is an all-purpose, modern 3D graphics engine and game development kit, feature complete to get you started quickly.
Cafu is available to everyone as 100% free software under the GNU General Public License (GPLv3). It can be used to create a variety of 3D applications, including games, simulations, and training and architectural software. Written in C++, the tools, libraries and framework have been designed to make the development of new games and other 3D applications easy. They are actively and continuously developed in order to provide the latest technology.
CityEngine - CityEngine provides professional users in entertainment, architecture, urban planning and general 3D content creation with a unique early design and modeling solution for the efficient visualization of 3D urban environments. A free trail version is available for 30 days.
Darkwynter - The DarkWynter engine is designed for students, researchers, and industry personnel interested in rapidly prototyping 3D applications. It has been constructed in response to the community's need for a light-weight modular system which can support a variety of research and educational requirements.
Delta3d - Delta3D is a full-function game engine appropriate for a wide variety of modeling & simulation applications.
Endorphin 2.7.1. - Endorphin 2.7.1. is a free, time-unlimited learning edition of Endorphin a 3D animation tool based on Dynamic Motion Synthesis.
OPAL - OPAL is a high-level interface for low-level physics engines used in games, robotics simulations, and other 3D applications. Features a simple C++ API, intuitive objects (e.g. Solids, Joints, Motors, Sensors), and XML-based file storage for complex objects.
Open CASCADE - Open CASCADE Technology, 3D modeling & numerical simulation is a software development platform freely available in open source. It includes components for 3D surface and solid modeling, visualization, data exchange and rapid application development
Openscenegraph - The OpenSceneGraph is an open source high performance 3D graphics toolkit, used by application developers in fields such as visual simulation, games, virtual reality, scientific visualization and modelling. Written entirely in Standard C++ and OpenGL it runs on all Windows platforms, OSX, GNU/Linux, IRIX, Solaris, HP-Ux, AIX and FreeBSD operating systems.
OpenSimulator - OpenSimulator is an open source multi-platform, multi-user 3D application server. It can be used to create a virtual environment (or world) which can be accessed through a variety of clients, on multiple protocols. OpenSimulator allows virtual world developers to customize their worlds using the technologies they feel work best - we've designed the framework to be easily extensible. OpenSimulator is written in C#, running both on Windows over the .NET framework and on *ix machines over the Mono framework. The source code is released under a BSD License, a commercially friendly license to embed OpenSimulator in products.
StarLogo TNG - StarLogo TNG is the Next generation version of the Starlogo modelling and simulation software. It uses 3D graphics to make more compelling and rich games and simulation models.
SimplyCube - The SimplyCube BETA Version by SimplySim is an all-in-one software tool designed to allow anyone to create real-time 3D applications such as simulations, serious games or virtual reality applications. SimplyCube contains a simulation engine and a toolbox of 3D editors.
Visual3D Game Engine - The Visual3D Game Engine is an All-in-One Development Tool for Games, MMOs, Simulations & Virtual Worlds powered by Microsoft XNA. A free trial version is available for download.

Aerodynamics Modelling

APAME - APAME is a 3D Panel Method program for calculating aerodynamic forces and moments about an aircraft. It is published under GPL-General Public License.

Aerospace Simulation

E-AIRS is an e-Science application portal for aerodynamic researches. The system supports the full procedure of CFD(Computational Fluid Dynamics) analysis, the remote experiment, integrated analysis of numerical and experimental researches, and the collaboration solution
CEASIOM - The CEASIOM application is a free Conceptual Aircraft design tool which runs under either Windows or Linux, and it only requires a MATLAB® license.

Agent Based Simulation

MASON - MASON is a fast discrete-event multiagent simulation library core in Java, designed to be the foundation for large custom-purpose Java simulations, and also to provide more than enough functionality for many lightweight simulation needs. MASON contains both a model library and an optional suite of visualization tools in 2D and 3D.
Lapsang - Lapsang is an Agent-based, discrete time, manet simulator

Analytical Simulation

Canopy - Canopy provides an open and intuitive environment for scientific and analytic computing.

Complexity Chaotic Systems Simulation

Raptor - Raptor is a Complexity Chaotic Systems Simulator. You can use it to simulate living organisms, ecological or social systems, planets, chemical reactions, gravity and more.
Furthermore, you will have the possibility to use this software as an Artificial Life (AL) Simulator. You just have to create different types of entities, load them into a new environment and watch them evolve together.

Discrete Event Simulation

erlSim - erlSim, is a discrete event simulator written in erlang and which is available at
sourceForge takes advantage of erlang’s high concurrency and speed of execution. It also includes several random distributions that are typically used in simulations such as the triangular and normal distributions.
GeneSim - GeneSim is an open source code generator for simulators of dynamic systems. GeneSim reads the specification of a dynamic system and produces the code that simulates the system. The specification is expressed using UML or SysML. Code is generated in object-oriented languages like C++, Java, C#.
JaamSim - JaamSim is a free and open source discrete-event simulation environment which includes a drag-and-drop user interface, interactive 3D graphics, input and output processing, and model development tools and editors. JaamSim is developed by Ausenco as the foundation of all our simulation applications. It represents about 10 man-years of effort since 2002 and is under continuous development to support our simulation projects. JaamSim is used daily by our team of 19 simulation analysts and programmers
Tortuga - Tortuga developed by the MITRE Corporation, is a software framework for discrete-event simulation in Java. A Tortuga simulation can be written either as interacting processes or as scheduled events. A Tortuga simulation can have thousands of entities, and can be part of a larger Java system.

Electrical Simulation

FeMOS - FeMOS is a Finite element simulation for double-gate MOSFET transistor. It calculates ballistic transport properties such as current-voltage characteristic, self-consistent potential, electron density, local density of states, and transmission curve. Nonequilibrium Green's function (NEGF) technique in Mode Space basis is used as the framework of the simulation.
The code is written in Octave scripting language. Octave is a high-level language, primarily intended for numerical computations. It is highly compatible with Matlab.

Electron Simulation

SIMCOM - SIMCOM is a versatile software package for the simulation of electron diffraction contrast images of localized strain. Electron diffraction contrast imaging allows for the characterization of localized strain with micrometer to nanometer resolution. SIMCON was developed at MTM and IMEC as a part of the PhD research of Koenraad Janssens.

Electronics Simulation

Arduino - Arduino is an open-source electronics prototyping platform based on flexible, easy-to-use hardware and software. It's intended for artists, designers, hobbyists, and anyone interested in creating interactive objects or environments.

Energy Simulation

AFORS-HET - AFORS-HET: is used for the numerical simulation of Solar Cells and Measurements. It features are modelling of an arbitrary 1D sequence of semiconducting layers and interfaces, Equilibrium EQ, steady-state DC, small sinusoidal pertubation AC and general transient TR calculation mode, Arbitrary parameter variations and parameter fitting, Simulation of internal cell parameters: band diagram, local cell currents, recombination, phase shifts,...Simulation of various measurement techniques, Optical modelling, Interface modelling, Boundary modelling and Layer modelling.
gModeller is an energy analysis plugin (free for individual use),for Google SketchUp. Based on the gbXML standard for designing resource efficient buildings and specifying associated equipment, gModeller enables the building designer to decorate 3D SketchUp building models with gbXML surfaces and openings, to identify and label gbXML spaces, and to import and export gbXML models.
Popolo Project - Popolo Project is a collection of classes for calculating various heat transfer phenomena. The routines have been written from scratch in C#, and present a modern Applications Programming Interface (API) for .NET Framework programmers, allowing wrappers to be written for very high level languages. It contains classes to calculate solid conduction, convective heat transfer near wall surfaces, air ventilation, radiative heat balance of wall surfaces, transmitted solar radiation through a window, and so on. Users should build up these classes to simulate a whole complex building system.

Energy Networks Simulation

GridLAB-D - GridLAB-D is a new power distribution system simulation and analysis tool that provides valuable information to users who design and operate distribution systems, and to utilities that wish to take advantage of the latest energy technologies. It incorporates the most advanced modeling techniques, with high-performance algorithms to deliver the best in end-use modeling. GridLAB-D™ is coupled with distribution automation models and software integration tools for users of many power system analysis tools.

Environmental Modelling

FISDEV - FISDEV (Framework for Integrated Sustainable Development) is an open source, collaborative tool for Sustainable Development written in MIKE2.0 (Method for an Integrated Knowledge Environment) which is an Open Source methodology for Enterprise Information Management that provides a framework for Information Development.

Finite Element Modelling

Abaqus 6.9 Student Edition - Abacus 6.9 - The Abaqus Student Edition includes the core Abaqus products; Abaqus/Standard, Abaqus/Explicit, Abaqus/CFD, and Abaqus/CAE. Model databases are compatible with other academically-licensed versions of Abaqus so that students can perform increasingly sophisticated analyses on models originally created in Abaqus Student Edition. The full HTML documentation set provides a thorough, searchable resource for students to find detailed information.
Designed for personal educational use, the maximum model size for structural analysis and postprocessing is set to 1000 nodes; for fluid analysis, the limit is 10000 nodes. Access to features requiring compilers (user subroutines, Abaqus Make, C++ ODB API), parallel execution, or add-on products has not been included. Replay and journal files are not available for Abaqus/CAE.
FEMLAB - FEMLAB is an interactive program for the numerical solution of ordinary and partial differential equations based on the Finite Element Method in adaptive form with automatic error control.
FreeFem++ is an implementation of a language dedicated to the finite element method. It enables you to solve Partial Differential Equations (PDE) easily. Problems involving PDE (2d, 3d) from several branches of physics such as fluid-structure interactions require interpolations of data on several meshes and their manipulation within one program. FreeFem++ includes a fast 2^d-tree-based interpolation algorithm and a language for the manipulation of data on multiple meshes (as a follow up of bamg).
FreeFem++ is written in C++ and the FreeFem++ language is a C++ idiom. It runs on any Unix-like OS (with g++ version 3 or higher, X11R6 or OpenGL with GLUT) Linux, FreeBSD, Solaris 10, Microsoft Windows (95, 98, 2000, NT, XP, Vista) and MacOS X (native version using OpenGL). FreeFem++ replaces the older freefem and freefem+.
Meep - Meep (or MEEP) is a free finite-difference time-domain (FDTD) simulation software package developed at MIT to model electromagnetic systems, along with our MPB eigenmode package.
MOR for ANSYS - MOR for ANSYS writes the system matrices of a reduced system in the Matrix Market format. It is possible to work with the reduced model in MATLAB/Simulink (see below examples from MOR for ANSYS users), Mathematica (see Post4MOR) and Python (see Post4MOR). Results of simulation with the reduced model can be postprocessed directly in ANSYS. Finally, we have experience with converting the reduced model to Saiber MAST and VerilogA.

Fluid Dynamic Modelling

Khamsin - a Google Sketchup Plugin for Computational Fluid Dynamic (CFD) Modeling
PHOENICS - PHOENICS is a general-purpose software package which uses the techniques of CFD (i.e. Computational Fluid Dynamics) to predict quantitatively: how fluids (air, water, steam, oil, blood, etc) flow in and around: engines, process equipment, buildings, human beings, lakes, river and oceans, and so on; what are the associated changes of temperature and of chemical and physical composition; what are the associated stresses in the immersed or surrounding solids.

Health Modelling

CardiacSimu - Cardiacsimu is a 3D cardiac model writen in C++ with high portability. It provides a platform for electrophysiological study. It can simulate action potential (AP) as well as propagation of the excitation according to AP waveform. It can also generate the isochronal map and isopotential map. Most exciting features of this tool set is total configuration of the simulation and anatomic structure. CardiacSimu can import any part of heart into simulation and make it discrete into units named simulating cell.The profile of single cell is configurable.
GIMIAS - GIMIAS is a workflow-oriented environment for solving advanced biomedical image computing and individualized simulation problems, which is extensible through the development of problem-specific plug-ins. In addition, GIMIAS provides an open source framework for efficient development of research and clinical software prototypes integrating contributions from the Physiome community while allowing business-friendly technology transfer and commercial product development.
STEM - The Spatiotemporal Epidemiological Modeler (STEM) tool is designed to help scientists and public health officials create and use spatial and temporal models of emerging infectious diseases. These models can aid in understanding and potentially preventing the spread of such diseases.
Vital Sign Simulator - The vital sign simulator is intended for use in medical emergency training simulations. In combination with a (cheap) cpr-manikin, it offers a low-cost alternative to commercial high-tech patient simulation manikins. It is used with a split-screen system, one monitor with controls for the operator and one providing the vital signs to the trainees. Heart rate, oxygen saturation, respiratory rate, blood pressure and various moving ecg-samples can be set and changed at any time by the operator. A trainee-side interface for (optionally synchronized) de-fibrillation is implemented, pacing is currently under development.

Logistics/CIM Simulation

ARENA Academic -ARENA Academic
- InsightMaker 2.0 - InsightMaker 2.0 is a web based modeling and simulation environment which provides for online development and simulation of stock & flow models. Because it is a web based environment it allows for easy sharing of models among a number of people with no worry as to whether everyone has the right software.

Micro-simulation

JAMSIM - JAMSIM is a framework for creating microsimulation models in Java. It provides code and packages for common features of microsimulation models for end users.
JAMSIM models run as standalone programs with a friendly GUI without requiring technical expertise. For further details see the requirements outline or this JAMSIM paper.
LIAM2 - LIAM2 is a tool to develop (different kinds of) microsimulation models.
Modgen - Modgen (Model generator) is a generic microsimulation programming language supporting the creation, maintenance and documentation of dynamic microsimulation models. Several types of models can be accommodated, be they continuous or discrete time, with interacting or non-interacting populations.

Molecular Dynamics Simulation

GROMACS - GROMACS is a versatile package to perform molecular dynamics, i.e. simulate the Newtonian equations of motion for systems with hundreds to millions of particles.
It is primarily designed for biochemical molecules like proteins, lipids and nucleic acids that have a lot of complicated bonded interactions, but since GROMACS is extremely fast at calculating the nonbonded interactions (that usually dominate simulations) many groups are also using it for research on non-biological systems, e.g. polymers.

Monte Carlo Simulation

Analytica - Analytica s a visual tool for creating, analyzing, and communicating decision models. You can download a free 30-Day trial version.
MCSim - GNU MCSim is a simulation package, written in C, which allows you to: design your own statistical or simulation models (eventually dynamic, via ODEs), perform Monte Carlo stochastic simulations and do Bayesian inference through Markov Chain Monte Carlo simulations.

Multibody Simulation

Universal Mechanism Lite 4.0 - Universal Mechanism Lite 4.0 is intended for simulation of kinematics and dynamics of planar and spatial mechanical systems

Numerical Simulation

octave - Octave is a high-level interpreted language, primarily intended for numerical computations. It provides capabilities for the numerical solution of linear and nonlinear problems, and for performing other numerical experiments. It also provides extensive graphics capabilities for data visualization and manipulation. Octave is normally used through its interactive command line interface, but it can also be used to write non-interactive programs. The Octave language is quite similar to Matlab so that most programs are easily portable.
Scilab - Scilab is free and open source software for numerical computation providing a powerful computing environment for engineering and scientific applications. Scilab is released as open source under the CeCILL license (GPL compatible), and is available for download free of charge. Scilab is available under GNU/Linux, Mac OS X and Windows XP/Vista/7/8

Object-Oriented Simulation

OpenModelica 1.6 is an open-source Modelica-based modeling and simulation environment intended for industrial and academic usage. Its long-term development is supported by a non-profit organization – the Open Source Modelica Consortium (OSMC)
This OpenModelica 1.6 release primarily contains model analysis/flattening, simulation, and performance improvements regarding the multi-domain Modelica Standard Library 3.1 support, but also has an interesting new tool – the OMEdit graphic connection editor, a new educational material called DrControl for teaching control systems with Modelica, and an improved ModelicaML UML/Modelica profile with better support for cyber-physical modeling and requirement handling (see also www.openmodelica.org, and the ITEA2 OPENPROD project www.openprod.org).
The goal with the OpenModelica effort is to create a comprehensive Open Source Modelica modeling, compilation and simulation environment based on free software distributed in binary and source code form for research, teaching, and industrial usage.
TOMAS - TOMAS is a Tool for Object-oriented Modeling And Simulation

Online and Telecommunications Simulation

OMNET++ - OMNeT++ is an extensible, modular, component-based C++ simulation library and framework, with an Eclipse-based IDE and a graphical runtime environment. Domain-specific functionality (support for simulation of communication networks, queuing networks, performance evaluation, etc.) is provided by model frameworks, developed as independent projects. There are extensions for real-time simulation, network emulation, alternative programming languages (Java, C#), database integration, SystemC integration, and several other functions. OMNeT++ is free for academic and non-profit use.
X3D - X3D is the Open Standards for Real-Time 3D Communication/Simulation

Simulation Optimization

EMSO - EMSO is a whole environment which allows the user to do mathematical modeling, simulation, and optimization in an easy way. It is completely developed in C++. Available mainly for Windows and Ubuntu (Linux) operating systems, although it can also be compiled for another platforms.
YALMIP - YALMIP is a modelling language for advanced modeling and solution of convex and nonconvex optimization problems. It is implemented as a free (as in no charge) toolbox for MATLAB. The main motivation for using YALMIP is rapid algorithm development. The language is consistent with standard MATLAB syntax, thus making it extremely simple to use for anyone familiar with MATLAB.

Petri Nets

WoPeD - WoPeD is an open-source software developed at the Cooperative State University Karlsruhe under the GNU Lesser General Public License (LGPL). The main goal of this tool is to provide an easy-to-use software tool for modelling, simulating and analyzing workflow process and resource descriptions using workflow nets, an extended class of Petri nets initially introduced by Wil van der Aalst (TU Eindhoven).

Physics Simulation

Box2D - Box2D Box2D is a free open source 2-dimensional physics simulator engine written in C++ by Erin Catto and published under the zlib license.
Elmer 5.4.0 Elmer 5.4.0 is an open source multiphysical simulation software. Elmer development was started 1995 in collaboration with Finnish Universities, research institutes and industry.
Elmer includes physical models of fluid dynamics, structural mechanics, electromagnetics, heat transfer and acoustics, for example. These are described by partial differential equations which Elmer solves by the Finite Element Method (FEM).
Geant4 - Geant4 is a toolkit for the simulation of the passage of particles through matter. Its areas of application include high energy, nuclear and accelerator physics, as well as studies in medical and space science.
PAL - Physics Abstraction Layer (PAL) is an open source cross-platform physical simulation API abstraction system.

Robotics Simulation

Anykode - Robotics Simulation. A free full version of the software is available for 30 days.
Open Dynamics Engine - Open Dynamics Engine (ODE) is an open source, high performance library for simulating rigid body dynamics. It is fully featured, stable, mature and platform independent with an easy to use C/C++ API.
The Player - The Player Project creates Free Software that enables research in robot and sensor systems.
V-REP - V-REP-the Virtual Robot Experimentation Platform--is a 3D robot simulator, with integrated development environment, based on a distributed control architecture: control programs (or scripts) can be directly attached to scene objects and run simultaneously in a threaded or non-threaded fashion. Manuals can be downloaded here.

Software Simulation

CoCoVila - CoCoViLa is a model-based software development platform. The platform provides a framework for developing visual specification languages. It includes a visual editor for drawing schemes and a synthesizer for generating Java programs from visual schemes and declarative textual specifications.

Species Habitat Modeling

Maxent Ver.3.3.3k - Maxent Software is based on the maximum-entropy approach for species habitat modeling

Sustainable Development Modelling

SDSIM is a System Dynamics model, and it is programmed in the STELLA simulation language. Links are provided to the STELLA software and an excellent System Dynamics primer. However, it is assumed that the reader is familiar with the System Dynamics method of system analysis and synthesis.
The objective of the Sustainable Development Simulation (SDSIM) is to analyze trade-offs between human development and economic development priorities. It is a global model, in the tradition of Limits to Growth and other similar projects. However, it attempts to take into account both material resources, which are limited, and human resources such as human wisdom, which are unlimited. The time window is 1950-2200, and the transition from consumerism to sustainability is expected to happen during the 21st century (i.e., approximately 2010-2100).

Traffic Simulation

SUMO - "Simulation of Urban MObility" (SUMO) is an open source, highly portable, microscopic road traffic simulation package designed to handle large road networks. It is mainly developed by employees of the Institute of Transportation Systems at the German Aerospace Center. SUMO is licensed under the GPL.
tsim - tsim is a simple train simulator written by Magnus Carlsson and Alois Goller and used on the Concurrent Programming course at Chalmers University of Technology. tsim uses X11 for its GUI, so you will need the X11 libraries and include files to compile and run tsim.

Training Simulation

The USIP Open Simulation Platform (USIP OSP) - The USIP Open Simulation Platform (USIP OSP) is an open source software tool to allow anyone to create, conduct, and share online training simulations quickly and easily. Further documentation can be found under OSPDocs.

Urban Modelling

UrbanSim - UrbanSim is a software-based simulation system for supporting planning and analysis of urban development, incorporating the interactions between land use, transportation, the economy, and the environment. You can also check out this link

Vehicle Simulation

ADVISOR® Advanced Vehicle Simulator - The ADVISOR software is a powerful vehicle simulator that can simulate a variety of vehicle types: passenger cars and trucks, transit buses, tractor trailers, and others; a variety of options for fuels: gasoline, diesel, ethanol, biodiesel, electricity, and hydrogen; as well as a variety of options for powertrain: conventional internal combustion engine, hybrid electric, plug-in hybrid electric, battery-electric, and fuel-cell.

Games

Game Development Software

Esenthel Engine - The Esenthel Engine is a complete cross-platform game development engine allowing to create fully featured AAA titles. It has been specifically designed for professional game development, which has been achieved by giving the developers full control over the game code mechanics, next generation graphics and a rich toolset drastically simplifying the game development process.
Gambit - Gambit is a library of game theory software and tools for the construction and analysis of finite extensive and strategic games. Gambit is designed to be portable across platforms, and runs on Linux, Mac OS X, and Windows.
Lua - Lua is a powerful, fast, lightweight, embeddable scripting language. Lua combines simple procedural syntax with powerful data description constructs based on associative arrays and extensible semantics. Lua is dynamically typed, runs by interpreting bytecode for a register-based virtual machine, and has automatic memory management with incremental garbage collection, making it ideal for configuration, scripting, and rapid prototyping.
recastnavigation - recastnavigation or Recast is state of the art navigation mesh construction toolset for games developed by MIT. The Library is free for commercial use and open source under the ZLib License.
Scratch - Scratch is a programming language from MIT, especially aimed at young children, that makes it easy to create your own interactive stories, animations, games, music, and art -- and share your creations on the web.

Adventure games

3D Adventure Studio – Create basic adventure games.
Adventure Builder – A basic DOS/WIN text adventure creator.
Adventure Game Engine – A nice adventure game engine for creating first-person adventure games in the style of Myst.
Adventure Game Studio – Another quality point-and-click third person adventure game creator.
Adventure Maker – The most notable feature of this toolkit is its ability to create games for the PSP and iPhone.
ADePT – A fairly old adventure game designer.
ADRIFT – A simple interactive fiction toolkit which allows you to create and run text games.
ALAN – A neat little program for creating interactive fiction.
Aiee! – A simple interface for designing and playing text adventures.
InterAx – Create first-person adventure games with no scripting.
QML - QML, the Quest Markup Language, is a free XML-based Choose-Your-Own-Adventure game system.
SLUDGE – A simple scripting language for creating adventure games. It isn’t the most intuitive option, but it is definitely functional.
Wintermute Engine – A very feature rich graphical adventure game creator.

RPGs

OO1 Action/RPG Maker - 001 Action/RPG Maker is a game creator where you can bring your Action RPG and RPG ideas to life! With a new twist to point-and-click (PnC) events, and a high level of customizability for characters, items, and magic
Dragon Age Origins Toolkit - The Dragon Age Toolset is everything you might need to create your own adventures in the Dragon Age game. You must have Dragon Age: Origins (PC) registered to download or use the Dragon Age Toolset.
Explorations - Explorations is a reasonably priced RPG maker. It features a powerful drag/drop map interface that makes creating professional looking game maps easy.
Hephaestus - Hephaestus is a freeware RPG. A map editor is included, and scripting is done in Java.
Official Hamster Republic RPG Construction Engine – This one has been around for ages, and for good reason - it’s a great option and has maintained an active community of developers for years.
REDkit (coming 2013)from CD Project - Free to owners of The Witcher2
RPG Maker XP - RPG Maker XP is the fourth PC version in the RPG Maker series of programs developed and published by Enterbrain.
RPG Toolkit Development System – A free, open source system for creating RPGs.
Sphere – Sphere requires quite a bit of scripting, but with that comes a lot of flexibility.

RTS Games

Freespace - Freespace Source Code Project, or SCP, refers to the open-source modification of the retail FreeSpace 2 RTS engine called FreeSpace Open
Pure power Tactical Engine - PPTactical is an engine for real-time strategy (RTS) and real-time tactics (RTT) games. The engine supports SDL and DirectX, has editors for maps and resources, scripted behaviour for units, battlegroups, missions, etc. Windows, Linux and Solaris are supported.

General 2D

AGen - AGen is a 2D engine and framework specifically designed for the easy and rapid development of games, game prototypes or other visual applications. AGen is completely Lua scripted and allows you to make games with little overhead and without a compiler.
Allegro Library - Allegro Library is a game programming library for C/C++ developers distributed freely, supporting the following platforms: Unix (Linux, FreeBSD, etc.), Windows, MacOS X and Haiku/BeOS. The functionality of the library includes support for basic 2D graphics, image manipulation, text output, audio output, midi music, input and timers, as well as additional routines for fixed-point and floating-point matrix arithmetic, unicode strings, file system access, file manipulation, data files, and (limited, software-only) 3D graphics.
BlitzPlus - BlitzPlus Gui 2D Engine, provides developers with a complete 2D programming solution for the PC, using a BASIC/C hybrid language. It is available for $60.
Chipmunk Physics Engine - The Chipmunk SDK is a portable open-source 2D physics engine written in C99 by Scott Lembcke and published under the MIT license.
Clean Game Library – Clean is a programming language/compiler, not a simple “point-and-click” game creation system.
Cocos2d - Cocos2d is a framework for building 2D games, demos, and other graphical/interactive applications. It uses Python and runs on platforms including the iPhone.
CONSTRUCT 2 - Construct 2 is a free, DirectX 9 game creator for Windows, designed for 2D games.
Game Maker 8 – A very clean, full featured 2D game development platform.
Golden T - Golden T Game Engine is a 2D game engine written in Java.
Hme - Height Map Editor Hme - Height Map Editor is a 2D program, used for creating, manipulating and viewing height maps.
Height Map Editor 1.3.1 - Height Map Editor 1.3.1 is a 2D graphic program that can be used for creating, viewing and manipulating height maps. A height map is a 2D representation of a 3D terrain. Each 'color' represents a height.
M.U.G.E.N. - MUGEN is a freeware 2D fighting game engine designed by Elecbyte, written in C which originally used the Allegro library. The latest versions of the engine now use the SDL library.
Multimedia Fusion – A very feature rich, but pricey, toolkit for developing interactive applications.
The PushbuttonEngine - The PushButton Engine is an Open Source, Flash game engine and framework for @D, RTS and RPG games.
Scrolling Game Development Kit – A complex but learnable toolset for the creation of side-scrolling games.
Stagecast Creator - Stagecast Creator is a toolset for creating 2D simulations, stories and games. You can download a free evaluation version.
SXDL - SxDL is a powerful and an easy to use 2D and 3D Game Development Framework for MS Windows and MS DirectX.
VERGE - VERGE is a free 2D Game Engine written in C++

General 3D

3DCakeWalk – A 3D game engine with lots of pre-written code, as well as the option to write your own scripts in Python.
The 3D Game Maker – This is so point-and-click simple that it’s more of a game itself than a game creation toolkit. (reasonably priced)
3D Rad – 3D Rad is a functional, if somewhat simplistic, 3D game engine and creation toolkit.
Aleph One - Aleph One is a free and open-source first-person shooter engine written in C based on the source code of Bungie Studios' Marathon 2: Durandal. Aleph One is available under the GNU General Public License
Antiryad Gx – A solid, free 3D game engine.
Ardor3D - Ardor3D is a scenegraph based 3D game engine, written entirely in Java and utilizing OpenGL for high performance gaming and visualization.It is based on the JMonkeyEngine.
Art of Illusion - Art of Illusion is a free, open source 3D modelling and rendering studio. Many of its capabilities rival those found in commercial programs. Highlights include subdivision surface based modelling tools, skeleton based animation, and a graphical language for designing procedural textures and materials..
Aquatica - Aquatica engine can be used to simplify the implementation of water surfaces in application with DirectX9 graphics. Aquatica engine is distributed in C++/HLSL source code format. The C++ source code is divided among 22 classes. Rendering uses DirectX9 libraries. Shaders are written in HLSL. Aquatica engine is fully object oriented. (free downloads are available but the actual cost of the software tool is very minimal)
Atmosphir - Atmosphir is a 3D adventure game and design tool.
Blender – is a free 3D graphics application written in Python, that can be used for modeling, UV unwrapping, texturing, rigging, water and smoke simulations, skinning, animating, rendering, particle and other simulations, non-linear editing, compositing, and creating interactive 3D applications, including video games, animated film, or visual effects.
Blender's features include advanced simulation tools such as rigid, realistic body, fluid, cloth and softbody dynamics, modifier-based modeling tools, powerful character animation tools, a node-based material and compositing system and Python for embedded scripting.
Blitz3D - Blitz3D provides a simple yet powerful environment for game creation - simple, because its based around the popular and easy to use BASIC programming language; and powerful, thanks to a highly optimized underlying 2D/3D engine.It is available for $100.
Cafu - The Cafu Engine is an all-purpose, modern 3D graphics engine and game development kit, feature complete to get you started quickly.
Cafu is available to everyone as 100% free software under the GNU General Public License (GPLv3). It can be used to create a variety of 3D applications, including games, simulations, and training and architectural software. Written in C++, the tools, libraries and framework have been designed to make the development of new games and other 3D applications easy. They are actively and continuously developed in order to provide the latest technology.
CAST II - CAST II is a free and open source 3D game engine (not only a graphics one) for Delphi and Free Pascal.
CityEngine - CityEngine provides professional users in entertainment, architecture, urban planning and general 3D content creation with a unique early design and modeling solution for the efficient visualization of 3D urban environments. A free trail version is available for 30 days.
CryEngine C++ Mod SDK V1.4 - CryEngine is a free 3D mod creator of the Crytek engine. To start, you need a copy of the Farcry game.
UPDATED CryEngine 3.5.6 SDK CryEngine 3.5.6 SDK free tool. The documentation files can be downloaded here
DarkBASIC – A reasonably priced engine which utilizes a modified, easy-to-learn version of the BASIC programming language.
Darkwynter - The DarkWynter engine is designed for students, researchers, and industry personnel interested in rapidly prototyping 3D applications. It has been constructed in response to the community's need for a light-weight modular system which can support a variety of research and educational requirements.
Delta3d - Delta3D is a full-function game engine appropriate for a wide variety of modeling & simulation applications.
Dim3 - Dim3 or Dimension3 is a free and open-source engine for creating 3D games. Some of the engines features include shader support, per-pixel lighting, bump, and specular mapping, real-time lighting and/or baked lighting, particles and other special effects, skeletal animation and customization through javascript. Projects run on OS X and Windows, editing suite is OS X only.
Doom 3 SDK - Doom 3 SDK is the mod version for creating Doom levels from Id Software.
FPS Creator – Easy to use package but a bit simplistic.
Game Studio – The programming language – Lite-C – was designed to be quick and easy, and the system can produce some very nice-looking games.
Genesis3D Genesis3D is a real-time 3D rendering environment for all of your real-time 3D needs
GtkRadiant - GtkRadiant is an open source, cross platform level editor for idtech games. It is also the official level design toolchain for id Tech 3 by id Software and is maintained by a community of volunteers. GtkRadiant is powered by the Gtk+ Project and released under a GPL license.
Irrlicht Engine - The Irrlicht Engine is an open source high performance realtime 3D engine written and usable in C++ and also available for .NET languages. It is completely cross-platform, using D3D, OpenGL and its own software renderer.
Modo 601 - Modo601 modo is the unique, artist-friendly 3D software that combines modeling, painting, animation and rendering in a fused workflow for designers and artists working in the areas of industrial design, architectural visualization, package design, game development, film and broadcast, education and scientific studies.
jMonkeyEngine - jME is an Open Source Java-based 3D Game Engine able to run state-of-the-art graphics.
The Nebula DeviceOgre3D - open-source 3D graphics rendering engine
Openscenegraph - The OpenSceneGraph OGRE (Object-Oriented Graphics Rendering Engine) engine is an open source high performance 3D graphics toolkit, used by application developers in fields such as visual simulation, games, virtual reality, scientific visualization and modelling. Written entirely in Standard C++ and OpenGL it runs on all Windows platforms, OSX, GNU/Linux, IRIX, Solaris, HP-Ux, AIX and FreeBSD operating systems. The class library abstracts the details of using the underlying system libraries like Direct3D and OpenGL and provides an interface based on world objects and other high level classes.
Panda3D - Panda3D is a game engine, a framework for 3D rendering and game development for Python and C++ programs.
Quake4 SDK - Quake 4 SDK is the Mod editor of Id Software based on Quake.
RAGE SDK Engine RAGE SDK Engine from Id Software studios. Can now be downloaded from Steam
Reality Factory – Several applications aimed at creatives who don’t want to touch a line of code.
Sandbox 3D Game Maker - Sandbox 3d Game Maker is an open source game design program for kids and adults. Through the in-game and cooperative editing and focus on ease of use the program is easy enough for kids to use but powerful enough for full game projects.
SDK - SDK Source Engine from Valve.
Silent Walk FPS Creator – A clean, simple, and overall very nice FPS development kit. The download link is at the bottom of the web page.
SimplyCube - The SimplyCube BETA Version by SimplySim is an all-in-one software tool designed to allow anyone to create real-time 3D applications such as simulations, serious games or virtual reality applications. SimplyCube contains a simulation engine and a toolbox of 3D editors.
Shiva 3D - Shiva 3D is a 3D Game Engine with Development Tools for Mac, PC and mobile devices. The personal Learning Edition is free for download.
StarLogo TNG - StarLogo TNG is the Next generation version of the Starlogo modelling and simulation software. It uses 3D graphics to make more compelling and rich games and simulation models.
Torque 3D - Torque 3D is the best full source, open source solution available. It is also our flagship engine built on the core strengths of our Front Line Award-winning Torque Game Engine Advanced. Torque 3D has been re-architected for maximum flexibility and performance across a wide-range of hardware. Torque 3D comes equipped with a full suite of tools to allow your team to excel and produce high-quality games and simulations. Torque 3D supports Windows and Browser-based web deployment out of the box.
Unity 3D - Unity, a subset of the commercial game development tool Unity Pro, is available for use to developers subject to certain conditions
Unreal 3D Development Kit - Features all the tools you need to create great games, advanced visualizations and detailed 3D simulations.
Visual3D Game Engine - The Visual3D Game Engine is an All-in-One Development Tool for Games, MMOs, Simulations & Virtual Worlds powered by Microsoft XNA. A free trial version is available for download.
XNA - Microsoft XNA, through its XNA Creators Club Online offers you as student, hobbyist or small game studio the ability to create games using XNA Game Studio Express, DirectX, and other XNA gaming tools and technologies.
ZGameEditor - ZGameEditor is a tool for creating small 3D arcade style games, demos and screensavers.

Online

Arianne - An open source multiplayer online role playing framework.
Byond – A simple scripting language which allows you to create multiplayer online games, which are played through the Byond software.
Croquet - Croquet is a powerful open source software technology that, in the form of the Croquet Software Developer's Kit (Croquet SDK), can be used by experienced software developers to create and deploy deeply collaborative multi-user online virtual world applications on and across multiple operating systems and devices.
Cycon Online Gaming Engine - The Cycon Online Gaming Engine or COG Engine Project is an Open Source project aimed at simplifying the creation of online video games. Users can make their own video games with no programming experience necessary, with a target audience ranging from children to gurus. Games can be played in a web browser (no software installation necessary!), and native ports of the development application are available for Linux and Windows.
DimensioneX - DimensioneX is a free Open Source MMORPG Multiplayer Game Engine. This game engine is actually a Java Servlet. It is not for a specific platform (i.e. PC or Mac) it will run on any Java-enabled web server (such as: Tomcat, also freeware).
Multiverse - A development tool for creating web-based games and 3D virtual worlds.
Open Metaverse - The Open Metaverse Foundation is a non-profit organization founded with the mandate of developing open technologies and open-source software related to the metaverse and virtual worlds.
Open Simulator - OpenSimulator is a 3D Application Server. It can be used to create a virtual environment (or world) which can be accessed through a variety of clients, on multiple protocols.
PIVOTE - PIVOTE is a virtual learning authoring system for virtual worlds. It was developed as part of the JISC funded PREVIEW project, where it was used to develop training material for Paramedic students at St George's Hospital and Kingston University.
Raknet - Raknet is a cross platform, open source, C++ game networking engine.
Realm Crafter – Realm Crafter is actually a large set of tools meant to ease the difficulty of building an MMO.
The Zombie Engine - The Zombie Engine is a complete game framework, editor and toolset for the creation of PC multiplayer action games. It is based on nebula2, the open-source 3D engine from Radon Labs.
VASSAL - VASSAL is a game engine for building and playing online adaptations of board games and card games. Play live on the Internet or by email. Vassal runs on all platforms, and is free, open-source software. Current release is 3.1.15

Image Editors

FantaMorph - Abrosoft FantaMorph is powerful and easy-to-use photo morphing software for the creation of fantastic photo morphing pictures and sophisticated morph animation effects.
GIMP - GIMP is an open source Linux image editing program.
Inkscape - Inkscape is an Open Source vector graphics editor, with capabilities similar to Illustrator, CorelDraw, or Xara X, using the W3C standard Scalable Vector Graphics (SVG) file format. Inkscape supports many advanced SVG features (markers, clones, alpha blending, etc.) and great care is taken in designing a streamlined interface. It is very easy to edit nodes, perform complex path operations, trace bitmaps and much more. We also aim to maintain a thriving user and developer community by using open, community-oriented development.
MS Paint - While not a particularly powerful image editing package, Paint is plenty good enough to create simple sprites.
Paint.NET – A free, open source image editing tool.
SpEdito - SpEdito is a simple sprite editor and code generator for z88dk
Sprite Studio - Sprite Studio is a reasonably priced sprite editor
Swish - Swish is a quite simple software, which allows the creation of any kind of interactive animations. Those animations can integrate texts, pictures, graphs and sounds. Swish movies can be embedded in web pages and played through the Flash Player plug-in, now included in most browsers.

3D Modeling

Abyssal Engine - The Abyssal Engine is a powerful professional game creation tool kit and rendering system for creating quality 3D software. The technology is designed to reduce development time while empowering developers with a strong suite of tools needed to produce great visual effects and immersive online or offline worlds. The technology allows the developer to create everything from single player RPG titles, Real Time Strategy Games, to Multiplayer and Massively multiplayer products as well as simulation applications. (The tool has a 30 day free trial period)
Alice - Alice is an innovative 3D object-oriented programming environment that makes it easy to create an animation for telling a story, playing an interactive game, or a video to share on the web.
Bullet - Bullet is an open source software multi-threaded 3D collision detection, soft body and rigid body dynamics library (physics engine) for games and visual effects in film.
Blender - Blender is a professional quality open source rendering, modeling and animation studio.
C4 Engine - The C4 Engine is a computer game engine developed by Terathon Software that can be used to create games for Windows (XP and Vista), Mac OS X (version 10.5), and the PlayStation 3 game console. (This one does have a cost of at least $250/user, so this is one of the cheapest of the professional game development software packages)
CAL3D - Cal3D is a skeletal based 3D character animation library written in C++ in a platform-/graphic API-independent way. Originally designed to be used in a 3D client for Worldforge, it evolved into a stand-alone product which can be used in many different kinds of projects. It supports combining animations and actions through a "mixer" interface, and work is currently underway to integrate morph targets (interpolating between one mesh and another, using the same vertex sequence) easily into the system.
Cipher - Cipher is a 3D game engine offering everything from fast and visually stunning graphics to support for compressed pak files. It allows programmers to create state of the art games using a simple but powerful SDK.
Cipher is a commercial game engine and is available for licensing right now for only $100.
Crystalspace3d - Crystal Space is a mature, full-featured software development kit (SDK) providing real-time 3D graphics for applications such as games and virtual reality. It is free (LGPL) and cross-platform (Windows, GNU/Linux, Mac OS X).
Endorphin 2.7.1. - Endorphin 2.7.1. is a free, time-unlimited learning edition of Endorphin a 3D animation tool based on Dynamic Motion Synthesis.
Fisix Engine - The fisix engine is a verlet based physics engine for flash written in Actionscript 3.0. This engine is aimed towards use in games and other relatively cpu intensive real-time applications.
K-3D - K-3D is free-as-in-freedom 3D modeling and animation software. It combines flexible plugins with a visualization pipeline architecture, making K-3D a versatile and powerful tool for artists.
Milkshape 3D - Milkshape is a very decent shareware modeler. It is less complex than Softimage and Blender.
Newton Game Dynamics - Newton Game Dynamics s an integrated solution for real time simulation of physics environments. The API provides scene management, collision detection, dynamic behavior and yet it is small, fast, stable and easy to use.
PAL - Physics Abstraction Layer (PAL) is an open source cross-platform physical simulation API abstraction system
Softimage|XSI Mod Tool - A free version of their professional modeling tool for hobbyists.
Torque 3D - Torque 3D is one the most easy-to-use game creation platforms available. A basic version is available for $100.

Game AI

Echo Chamber Echo Chamber is a free datamining tool that allows programmers, artists, and designers to visually analyze and playback game sessions.
Havok - The Intel-sponsored Havok PC download is a binary-only bundle that includes all of the standard features and functionality of both the Havok™ Physics and Havok™ Animation products. The download includes Havok SDK libraries, samples, and technical documentation for software developers; as well as Havok's Content Tools for preparation and export of physical assets and characters directly from recent versions of popular 3D modeling and animation tools.
Interactive Track Generator for TORCS and Speed Dreams - This application uses Interactive Genetic Algorithms to generate tracks for the open-source racing games TORCS and Speed Dreams.
PathEngine - PathEngine is a sophisticated middleware tool-kit for the implementation of intelligent agent movement, built around an advanced implementation of points-of-visibility pathfinding on 3D ground surfaces. A test-bed only version is available for free download.

Serious Gaming

DX Studio 3.2 - DX Studio 3.2 is 3D Serious Game Engine which features a complete integrated development environment for creating interactive 3D graphics. The system comprises of both a real-time 3D engine and a suite of editing tools. Using DX Studio you can build complete real-time interactive applications, simulations or games, for standalone use or for embedding in other Microsoft Office/Visual Studio applications.
Game Show Presenter - Game Show Presenter is a presentation tool that lets you make your information fun by presenting it as a customized game show based on your quiz. This presentation software helps people to pay attention and to learn by putting your questions into a funny, TV-style quiz show.
ITyStudio - ITyStudio is an authoring software of multimedia educational content, allowing you, amongst others, to design and make Serious Games as well as customised questionnaires. A trial version is free of charge for 10 days.

Text Editor

Chat Mapper - Chat Mapper is a non-linear dialog editor.

Sound Engineering

OpenAL - OPenAL is a cross-platform 3D audio API appropriate for use with gaming applications and many other types of audio applications.
The library models a collection of audio sources moving in a 3D space that are heard by a single listener somewhere in that space. The basic OpenAL objects are a Listener, a Source, and a Buffer. There can be a large number of Buffers, which contain audio data. Each buffer can be attached to one or more Sources, which represent points in 3D space which are emitting audio. There is always one Listener object (per audio context), which represents the position where the sources are heard -- rendering is done from the perspective of the Listener.
YSE - YSE is a 3D sound engine targeted at audio art professionals and game developers. What sets YSE apart from similar software is the extensive DSP functionality. That aside, YSE is also very intuitive to use if compared to most other engines.
YSE is still very new and currently supports the Windows Platform only. Other platforms will follow in time. YSE comes with a remarkably small dll file, C++ header files and tutorial/example programs. Wrappers for other programming languages will be available later.

Video Capture and Benchmarking

Fraps - Fraps is a universal Windows application that can be used with games using DirectX or OpenGL graphic technology. In its current form Fraps performs many tasks and can best be described as: Benchmarking Software, Screen Capture Software and Realtime Video Capture Software.

Game Hardware

Kinect for Windows - Kinect for Windows shows how to build applications and experiences using K4W.

other applications related to simulation and modelling

ADONIS - ADONIS:Community Edition is a free tool provided by the BOC Group which serves as a perfect entry point to professional Business Process Management and as a way to become familiar with ADONIS. ADONIS:CE is a functional and feature rich stand-alone version of ADONIS with few limitations in comparison to the commercial edition. ADONIS:CE is completely free of charge and does not have any time related restrictions.
Care2x- Care2x is the open source hospital information system.
DISLIN - Scientific Plotting Software
Julia - is a high-level, high-performance dynamic programming language for technical computing, with syntax that is familiar to users of other technical computing environments. It provides a sophisticated compiler, distributed parallel execution, numerical accuracy, and an extensive mathematical function library.
iCub -iCub is an open source cognitive humanoid robotic platform. The software installation can be found here, while the manuals can be found here.
KiCad EDA - KiCad EDA is an open source software suite for electronic design automation (EDA) made for designing schematics of electronic circuits and printed circuit boards (PCB). KiCad is developed by the KiCad Developers Team, and features an integrated environment with schematic capture, bill of materials list, PCB layout and much more.
Mimosa - Mimosa is a scheduling and course planning software for use in any kind of school and university of varying type and size. Besides academic timetabling, Mimosa suits perfectly to schedule conferences and in business and organisations. The application is fast and slim, versatile, user-friendly with a large capacity. Mimosa has a very rich set of efficient optimisation tools and interactive timetabling selections even for the most demanding scheduling challenges.
Mirth Connect- Mirth Connect is a comprehensive open source integration solution that can handle all of the work to transform and route healthcare data
Nike Environmental Design Tool - Nike is releasing its Environmental Apparel Design Tool with supporting data and methodology for public review.
ProM - ProM is a generic open-source framework for implementing process mining tools in a standard environment.
R Project - R is a free software environment for statistical computing and graphics. It compiles and runs on a wide variety of UNIX platforms, Windows and MacOS.
SIMILE Widgets - SIMILE Widgets is an open-source “spin-off” from the SIMILE project at MIT. Here we offer free, open-source web widgets, mostly for data visualizations.
Slash/A - Slash/A is programming language and C++ library for quantitative applications of linear genetic programming (GP). Genetic programming is a machine learning method for randomly 'evolving' computer programs until they perform a given desired task. Linear means that codes are expressed as a simple string of instructions as opposed to the more complex tree structure originally adopted by GP practitioners.
Spark - Spark is an open source cluster computing system that aims to make data analytics fast — both fast to run and fast to write. To run programs faster, Spark provides primitives for in-memory cluster computing: your job can load data into memory and query it repeatedly much quicker than with disk-based systems like Hadoop MapReduce.
Spice - The Spice project aims to provide a complete open source solution for interaction with virtualized desktop devices.The Spice project deals with both the virtualized devices and the front-end. Interaction between front-end and back-end is done using VD-Interfaces. The VD-Interfaces (VDI) enable both ends of the solution to be easily utilized by a third-party component.

Links to more free simulation/modelling and games software

Simulation Software
Modelling Software
Game Development Software
Multimedia Software
Evaluations of Workflow Products