Well no, we will never support HolyC, whatever that is. Maybe Nim already runs on TempleOS, maybe not but we don't officially support it and I don't accept patches for adding support for it. Likewise we don't support Oberon (the OS, not the language) nor Plan 9.
https://youtu.be/UCgoxQCf5Jgis a pretty good video about the creator of TempleOS and HolyC @Araq or for anyone else that is curious. It's a pretty sad but fascinating story I'd you've never heard of Terry Davis before or his story.