1. Basilisk
2. GameFrame for Java
3. Golden T game engine
4. Pulpcore
5. Genuine Advantage Game engine
6. Gentus Easyway
7. Slick2D
8. JGame
9. Game Gardens

Physics Engine

1. Tokamak ( Open source physics api)
2. APE (Actionscript Physics Engine)
3. Flade ( Flash Dynamics Engine)
4. Fisix Engine (Another flash actionscript engine)
5. Simple Physics Engine
6. Newton game dynamics
7. Novodex
8. ODE

Sound Libraries

1. FMod
2. OpenAL

Quantum Engine is an cross-language 32bit native code compiler with an advanced 2D game engine for PC’s running Microsoft Windows® and uses Direct3D® for hardware accelerated rendering. It’s robust, designed for easy of use and suitable for making all types of 2D games and other graphic simulations. Your code can compile to a stand-alone EXE and/or to dynamic loadable compiled units (runtime packages). The core game engine consists of a high-level object oriented game application framework with a plethora of classes and routines to allow you to rapidly and efficiently develop your graphics simulations. There is support for surfaces, textures, sprites, audio, streams, archives, configuration files, render targets, swap chains, databases and much more.

Quantum engine is free of charge for freeware projects but if you plan to sell them then you need to buy license for the game.

Makers of unreal tournament released the development kit for free.They offer this SDK free and for almost any type of game development usage be it commercial or presentation or for education,personal,collaborative project.

System requirements are higher so if you’re with limited system resource then this SDK is not for you.

Minimum:

* Windows XP SP2 or Windows Vista
* 2.0+ GHz processor
* 2 GB system RAM
* SM3-compatible video card
* 3 GB Free hard drive space

Recommended for Content Development:

* Windows Vista 64 SP2
* 2.0+ GHz multi-core processor
* 8 GB System RAM
* NVIDIA 8000 series or higher graphics card
* Plenty of HDD space

Check the UDK site here.

It also has two sub-projects for specific media support. First project is FFMPEG-Java and second is Theora-Java.

What is FMJ ?

FMJ is an open-source project with the goal of providing an alternative to Java Media Framework (JMF), while remaining API-compatible with JMF. It aims to produce a single API/Framework which can be used to capture, playback, process, and stream media across multiple platforms.

From where to get it ?

You can get more information about FMJ and download it from here.

Free or Paid ?

It is paid application. It costs €9.95 bucks for the product.

What are the features ?

- Editor with example scripts
- More than 55 affectors, emitters, observers, handlers and renderers
- PhysX support
- Particle System LOD
- Soft particles
- Atlas texture support and atlas tool
- Manual, tutorial and API description
- And more …

New version of particle universe is just released. That is version 1.1, so if you want to check it you can do so at FXpression site.

Here is list of free graphics related tools. 

Vector-based drawing tools

Vector graphics is represented by points, lines, curves and surface instead of pixel as within bitmap graphics.

InkScape

Inkscape is having interface similar to CorelDraw. It is basically an SVG editor. 

Skencil

This is another vector drawing application. It’s interactive and flexible interface makes it good tool for illustration, diagrams and other graphics purpose. Unfortunately, it’s not for windows users.

Sodipodi

It’s also an SVG editor like Inkscape. But its interface is more like GIMP (image manipulation program). 

Synfig

Synfig is more of a 2D animation tool so it also fits in the category of vector illustrator tool. 

Raster-based drawing tools

These tools are more for bitmap drawing tools. 

GIMP 

GIMP stands for gnu image manipulation program. It is free/open source software that you can use for raster drawing as well as picture manipulation as well. 

Paint.NET

This software started as replacement for MS paint. But later more features incorporated in it. 

Krita

It is included in Koffice suite so if you’ve KDE installed on your linux box then chances are that this tool comes installed with Koffice suite. It has features similar to GIMP. 

KolourPaint

This is another KDE application for linux users. It has interface similar to MS Paint. 

Graphciscale

There is freeware version with some limited features available. You can use freeware version to carry out graphics work of game. 

Terrain & Map editing tools

For 2D & 3D there are few free alternatives for terrain & map editing tools. Some of them are listed below:

TileStudio

Tilestudio is geared more towards 2D games. It has following features: Level editor, Sprite editor, Map editor, output in multiple programming languages. 

DeleD-Lite

3D level designer with limited functions in lite version. 

Terragen

A tool for rendering landscapes, good for background graphics.  

3D modeling

There are plenty of open source/freeware tools available for 3D modeling.

Blender

This is very famous 3D modeler around. It is free, open source and has game engine as well. It is even used to develop commercial quality animated movies with this tool. 

OpenFX

This is another powerful 3D modeler used by many open source games.

Wings3D

It is also free and comes with steep learning curve. If you like working with blender then you’ll love this tool as well. 

Misfit-Model 3D

This is also 3D modeler which supports many file formats and allows skeletal animation. 

Truespace

This software supports Modeling, animation, rendering and it is free as well. 

This list is work in progress. If you know any free-resource in any category not listed then please feel free to post about it in comments.

What are sprites?

Sprites are graphical objects like trees/clouds/hero/villans/bullets and so much to list. Sprites can be created with help of image editing tools like photoshop, paint.net, Gimp etc. If you’re not into the sprite designing then you can even download the free & legal sprites for your game. There are many open source games that allows you to reuse the sprites in your game.

For demonstrational purpose you can get the sprites from http://spriters-resource.com

Sprite editor

Gamemaker has built in sprite editor that allows you to choose the actions of animated sprite. We have two ways to open sprite editor : First you can right click on “Sprite” folder in left hand sidebar and click “New Sprite”, this will open up the sprite properties dialog.

Second way to open sprite properties is click on “Resources” menu and then click on “Create Sprite”. 

To name your sprite click the “Name” field and enter the name of your sprite. To load the graphics(sprite) you have to click “Load sprite” button. That will open up the Sprite editor window where you can set the width & height of the sprite.

Now make your sprite “transparent” so that it can easily blend with the rest of the graphics in the game. You can easily see the difference when you uncheck this option, your character shows colored edges which sets itself differently from the rest of the game graphics.

Once you’ve done with it then click OK to close the dialog box.

Animated Sprites

If you’re using animated sprites then you’ve to cautiously use the width & height in Edit sprite dialog box. so that each frame of the sprite is properly selected without cutting any edge of character/object. 

While creating animated sprites you can select smooth edges option in ‘sprite properties” dialog box.

Hope this information helps.If you’ve any questions then feel free to post them here.