The Docker client (cli) is easy to port - it's mostly just an elaborate frontend to the socket/API. Every other OS just runs Linux in a VM. Focusing on integrating the VM with the usual development workflow is the lowest hanging fruit, provides the best ROI, and is relatively future-proof.
Unless you mean running containers in production - I think OCI is a much better target in that case.
Unless you mean running containers in production - I think OCI is a much better target in that case.