The subset of the list that supports in-process calls and which allows for zero-copy (and, realistically, probably mutually mutable) data sharing of its types i

The subset of the list that supports in-process calls and which allows for zero-copy (and, realistically, probably mutually mutable) data sharing of its types is shorter still. I think the useful definition of "ABI" includes more than just API discoverability (aka what D-Bus provides if you take away the RPC system).