The paper mentions it uses Diffusion Transformers. The open source implementation that comes up in Google is Facebook Research's PyTorch implementation which is a non-commercial license. https://github.com/facebookresearch/DiT

Is there something equivalent but MIT or Apache?

I feel like diffusion transformers are key now.

I wonder if OpenAI implemented their SORA stuff from scratch or if they built on the Facebook Research diffusion transformers library. That would be interesting if they violated the non-commercial part.

Hm. Found one: https://github.com/milmor/diffusion-transformer-keras