If you use Python, you might know a library called Manim. It is first a personal project by 3b1b and you can now (well it always has been open source, but it finally got usable documentation and maintenance recently, around 2020) use it for yourself as well.
There are two main versions of manim:
- 3b1b/manim: A version that is used and maintained by 3b1b himself, used in his Youtube videos.
- ManimCommunity: forked from manim in 2020, more stable, document, etc. It is recommended to use this repo for your projects.
It is easy to get started, a good way to make your own projects, or adding custom animations to your presentation.