Are we talking with respect to the overall RobotFramework ecosystem with REST (for remote library) support in:
- RobotFramework (as the REST client for the library)
- RobotFramework remote library protocol specification, amended to include REST as an option and how it would work in REST
- RobotFramework remote library server implementations
If the whole ecosystem, that would be significant work, and adoption besides yourself would require the RF team to accept your PRs. But if you just needed to serve some of RF’s libraries (native or 3rd party ones) over REST or other RPC, you could extend the applicable remote server implementations (python, java, .NET, etc.) to offer an alternate interface to run the keywords, which is a lot easier to do. Then using said patched servers you can run compatible RF libraries that are in the same language as the patched server, over REST/RPC.