[nox101]

Sounds like COM/DCOM from ~1995. Every API had a public interface including a description. You could open the DCOM Inspector, browse all the APIs, and see the type signature of every function and its docs.

[pjmlp]

Still is COM from 2025, given its relevance on Windows, even more since Vista, as all Longhorn ideas were remade in COM.

However the tooling experience is pretty much ~1995, with the difference IDL is at version 3.0.