Synfig Studio - Just another WordPress site
PaintBerri - PaintBerri is a free art site that offers an awesome oekaki community.
Animation Paper - Animation Paper is a software package for doing 2D animation.
okekai - A small community site where you can draw, animate, and chat through pictures all for free
CrazyTalk Animator - CrazyTalk Animator, the next level of 2D animation. Create actors using any photo or illustration.
Brush Ninja - Hand-drawn Animated Gif Creator