Manim

If you need to create mathematical animations programmatically, this is the framework 3Blue1Brown made famous. You write Python classes that inherit from Scene, define mobjects like circles and equations, then orchestrate transformations with self.play(). It handles LaTeX rendering natively, which is essential for any serious math visualization work. The learning curve is real since you're coding animations rather than dragging keyframes, but that's the point. Once you understand the Scene/Mobject/Animation pattern, you can generate entire educational videos from code. Test with the low quality flag for speed, then render at high quality when you're done. The documentation and example gallery are solid resources for getting past the initial confusion.