software

• cross platform (mac, windows, linux)
• open source / open file formats
• easy to use
• stable

image manipulation

• GIMP
  • http://www.gimp.org/
  • "GNU Image Manipulation Program"
  • wikipedia: GIMP
  • free, multiplatform, (fairly) easy to use, fairly powerful
  • GIMPShop (http://plasticbugs.com/?page_id=294) - GIMP with a PhotoShop-like GUI

• Inkscape
  • http://en.wikipedia.org/wiki/Inkscape - open source vector graphics editor
  • vector graphics editor
  • outputs to .svg
  • no support for animation

sound editing

• Audacity
  • http://audacity.sourceforge.net/
  • wikipedia: Audacity
  • free, multiplatform, easy to install, easy to use

• Ardour
  • http://www.ardour.org
  • wikipedia: Ardour (audio_processor)
  • digital audio workstation suitable for a professional

animation and modeling

• Blender
  • http://www.blender.org
  • wikipedia: blender (software)

• SketchUp
  • http://sketchup.google.com/
  • free, propietary, mac/win, creates buildings for GoogleEarth
  • expensive "Pro" version with more features
  • 3D Warehouse http://sketchup.google.com/3dwarehouse
  • wiki - http://suwiki.org/

• KToon
  • http://ktoon.toonka.com
  • 2D animation toolkit
  • open source
  • can creat .swf (flash) output
  • unix

• Flash
  • propietry
  • in nearly all modern browsers
  • .swf file extension is what web browser downloads

• SVG
  • open source Scaleable Vector Graphics
  • supported by FireFox; not IE currently
  • http://en.wikipedia.org/wiki/Scalable_Vector_Graphics
  • http://en.wikipedia.org/wiki/Inkscape - open source vector graphics editor

• Synfig
  • http://www.synfig.com
  • open source 2d vector animation
  • not particularly mature yet

video

viewing

• coming

reading, transcoding, writing

• coming

• HandBrake - DVD to MPEG-4 ripper/converter
  • http://handbrake.m0k.org/
  • for Windows: third party port

editing

• Cinellera
  • http://cvs.cinelerra.org (community branch)
  • http://heroinewarrior.com/cinelerra.php3 (heroine virtual branch)

• LiVES (Lives is a Video Editing System; originally Linux Video Editing System)
  • http://lives.sourceforge.net/
  • open source; looks interesting

• Kino
  • "digital video for linux"
  • http://www.kinodv.org

• Avidemux
  • http://www.avidemux.org
  • (I'm still testing this one.)
  • wikipedia: Avidemux