This is a list of some various tools that can be used for developing your games.
- http://www.getpaint.net/ Paint.NET is a free image editing tool for Windows. It has a large database of plug-ins which vastly expand its capabilities.
- http://www.gimp.org/ GIMP is an open source, cross-platform image editing tool. It has a large variety of plug-ins, scripts, and brushes available.
- http://inkscape.org/ Inkscape is an open source, cross-platform vector graphics editor, similar to Adobe's Illustrator.
- http://www.blender.org Blender is a free 3D modelling and animation program. It's often held in high regard and boasts a full integrated physics engine along with python scripting support.
- http://audacity.sourceforge.net Audacity is an open-source audio manipulation program. It supports recording, editing, importing and exporting audio. MP3 files can be handled via an external LAME codec.