[CuriousCosmic]

It has a license now fwiw.

It's a pretty basic "free for non-commercial use, contact us for commercial use" license.

And the Inria rasterizer is not proprietary either. It's non-commercial open source with the option to purchase a commercial license.

These are perfectly reasonable tech stacks for research projects to build off of. If you have an issue with the license, implement it yourself based on the papers (which all outline the necessary details to do so).