OpenToonz - OpenToonz is an animation program that is a free software version of Toonz, the animation software...
MotionDen - Free online animated video maker
Synfig Studio - Just another WordPress site
Animaker - Animaker is an online do-it-yourself (#DIY) animation video maker that brings studio quality presentations within everyone's reach. Animated Videos, Done Right!
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Rocketium - A DIY video creation platform. Make videos in minutes using preset themes and templates.