22 Open-Source Repos to Replace After Effects—and the Whole List Got Stumped by One Question

Someone listed 22 open-source repositories on X, saying that together they can replace After Effects and form a complete motion studio. The original post claimed that they used Opus 5.5 plus this toolset to replace their old workflow, covering the entire pipeline from animation, physics, and 3D to sound and final delivery.

The list is divided into several sections by function.

For visuals and animation: Remotion lets you write videos in React; run npx create-video@latest to start a project. Anime.js orchestrates animations on a timeline and supports CSS properties, SVG, DOM attributes, and plain JS objects. mo.js handles shape bursts and motion effects. Theatre.js provides visual keyframe editing. Two.js handles vector scenes. D3 produces data-driven graphics.

In 3D and physics, Three.js builds scenes and cameras, Babylon.js handles real-time rendering, Drei provides ready-made components for React Three Fiber, Spark renders Gaussian splats, cables.gl connects visual nodes, Taichi runs physics simulations on the GPU, and SPlisHSPlasH handles fluids, foam, and splashes. Custom Shader Material lets Three.js materials use custom shaders. Hand-drawn animation is handled by OpenToonz.

For sound and post-production: Qwen3-TTS generates voiceover, Audacity cleans up and mixes, Subtitle Edit edits subtitles and timing, Auto-Editor automatically cuts silent sections, RIFE does frame interpolation for smooth slow motion, OBS records screen, and FFmpeg encodes for delivery.

The original post sums up the workflow in one line: idea → storyboard → build → animate → mix → export.

What's notable is that most of these tools are not new. Three.js, D3, and FFmpeg have long been infrastructure in their respective fields, and Anime.js has already reached V4. The change is in how they are connected. The first line of Remotion's README says "Make videos agentically"—hand the idea to an agent and get a video. The tools haven't changed; the hand calling them has.

The problem with the list is right there too. After installing 22 repositories, what you get is 22 sets of APIs to learn, not a studio. Someone in the comments asked directly: 22 sounds like too many—which three are the most important? The original post didn't answer.

Another reply is more practical: scripts, deadlines, payment, and rework determine the outcome more than the animation itself. A tool list solves whether you can make something; it doesn't solve whether anyone will watch it.

One detail was singled out separately: most product launch videos flash their titles faster than people can read them, and reading dwell time is the most easily underestimated part. That judgment is more useful than the entire tool list.

An easy pitfall to miss: Remotion's license is not purely open source, and some commercial scenarios require purchasing a license from the company; the README says this clearly. Before actually taking on work with it, read the LICENSE first.

To avoid detours, start with three. Remotion produces the visuals, FFmpeg finishes, and add one more in between as the project requires. As for the remaining dozen or so, look them up when you actually run into a specific problem.