OpenToonz - OpenToonz is an animation program that is a free software version of Toonz, the animation software...
Synfig Studio - Just another WordPress site
Animation Paper - Animation Paper is a software package for doing 2D animation.
Adobe Animate - Adobe Animate is a Flash, vector animation software.
CrazyTalk Animator - CrazyTalk Animator, the next level of 2D animation. Create actors using any photo or illustration.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.