Houdini: Carbon is available as a plug-in for Houdini (H18.5, H19.0 & 19.5) - only requires Houdini Core.
Maya: Carbon is available for Maya 2020, 2022, 2023, 2024
UE5: Carbon is available for UE5 for major projects.
C++: Additionally, you can license Carbon as a standalone C++ library.