AMD paid Some Guy in Poland to build a drop-in CUDA replacement that runs on their GPUs in secret for two years and now it's open source
it works: many CUDA software can run on HIP/ROCm without any modifications -- or other processes... Just run the binaries as you normally would while ensuring that the ZLUDA library replacements to CUDA are loaded. For reasons unknown to me, AMD decided this year to discontinue funding the effort and not release it as any software product. But the good news was that there was a clause in case of this eventuality: Janik could open-source the work if/when the contract ended.