Natron

Natron is a node-based compositing tool modeled on Nuke rather than After Effects, which is arguably the better paradigm to learn: rotoscoping, keying, tracking, and OpenFX plugin support for effects. For motion graphics and VFX shots that would otherwise mean After Effects, it’s the main open-source option, and Nuke tutorials often translate directly.

Development has been rocky — long dormant stretches with periodic revivals — so check the current state before building a workflow on it. It’s also compositing-only: no timeline editing, limited text/motion-graphics tooling compared to AE, and stability under heavy node graphs can wobble. Blender’s compositor is the actively-maintained alternative if Natron stalls again.