A socket is just a raw byte stream. It's a solid base layer, but you'll have to implement your own communication protocol on top, and it'll require copying the data from one process to another. A "stream" is the wrong metaphor for local data sharing.

The data is already in memory and the source program knows its "shape"; there should be an easy mechanism to provide access to that by default, like /proc or gdb but for arbitrary data structures and with better UI.