On Monday, we covered a variety of handy resources to use for our upcoming game jam. Here's list of the resourced we covered, highly useful for not only the game jam, but game development in general. All items here are free for most functionality, and are arranged in no specific order save for categories.
Before you jump into exploring these resources, note that 3D-related tools tend to have a much more significant learning curve, so we do not recommend attempting to develop a 3D game during the game jam without significant prior experience.
Stencyl - popular 2D game-creation software with visual scripting and integrated physics engine.
Game Maker Studio - speedy game-development tool with extensive community.
Construct 2 - 2D game-development engine.
Unity - strong 3D game-creation tool.
Ren'Py - Python-based visual novel creation engine, no prior programming experience necessary.
Pygame - popular Python extension for game creation.
Unreal Development Kit - complete 3D game-development engine. Beware: high learning curve.
Tigsource Assemblee Competition Part 1 - graphics for sound assets for public use
GraphicsGale - highly useful and (mostly) free pixel art creation program.
Photoshop CS2 - this old version of Photoshop is now free! Note that Windows 7 needs special support.
GIMP - standard free open-source program.
Pixen - open-source pixel-art creator for Mac OS X
Blender - free 3D graphics rendering software.
Audacity - powerful open-source sound-editing program.
Sfxr - instant 8-bit sound effect generator. Check out bfxr for flash version and cfxr for Mac version.
FreeSound - huge database of quality sound effects, under a variety of references.
Incompetech - another database of free sounds.
GarageBand - powerful tracking/SE tool for Mac.
Acid Xpress - free music recording and creation software for Windows.
Tiled - map-creation software for tile-based games.
MakeHuman - random 3D human model generator.
PolyCount - community for 3D art creation and game development.
ModDb - community for game modding.
Comment if you have more resources that you think fits on this page, and good luck if you are attending the Game Jam!