Open source software to make 2 animation

[Goldilock]

I'm helping a friend making teaching material, few concepts can get very complicated so my idea is making simple 2D animation on how these concepts interact and flow with each other.

 

Input on recommended open source 2D animation is appreciated. I've seen few ones but I can't tell which is good since I'm also pure beginner.

[Kisai]

Depends what exactly you want to do.

 

You can do 2D in Blender with the grease pencil. Probably not my first choice.

Toonz (OpenToonz https://opentoonz.github.io/ ) is probably the one I would recommend if you're trying to do traditional animation (eg draw frame by frame)

Synfig (https://www.synfig.org/ ) is for doing "cutout animation" 

Krita is a painting program that "can do animation" as well

 

Just be aware that nothing is "easy" with animation and they all require some basic art skill.