I built the core of the animation engine, and I think our wording may have created the wrong impression about how it was developed.

For the use case we have, we needed a fast animation engine. The engine didn’t begin as a port or rewrite of Manim. We originally built it under a different name as a standalone Rust/WebGPU 3D animation engine for real-time AI tutoring. I spent roughly two months building the renderer and animation system from scratch.

Our original engine had a different interface, different defaults and produced different visual results. Only after the engine was already working did we decide to make part of its Python interface compatible with ManimCE. We did that because many users already know the Manim API, and coding models are already familiar with its classes and common animation patterns. We spent substantial time matching ManimCE’s visual behavior as closely as possible. We believe this compatibility layer makes adoption easier; yet the underlying renderer, scene system, and implementation are our own.

So describing this as vibe coding Manim in Rust and then closing the source is inaccurate. The browser editor, rendering, and video downloads are free. You are free to write code, render and download videos as much as you want. The paid features are the AI-powered functionality, which are priced to cover their cost to us.

We respect that some people would prefer it to be open-source, but choosing not to open-source an independently developed engine is different from taking an open-source project and repackaging it as proprietary software.