Indeed, there is no shortage of open source ray tracers and renderers. That said, there are very few open source renderers with full OSL (https://github.com/ima

Indeed, there is no shortage of open source ray tracers and renderers. That said, there are very few open source renderers with full OSL (https://github.com/imageworks/OpenShadingLanguage https://github.com/imageworks/OpenShadingLanguage) support and the required features for animation and VFX works. I actually know only two (both actively developed): Cycles and appleseed.