Can two open sessions of Houdini on same machine talk to each other. See each other's data without having to cache first or copy/paste, or referencing a scene.
For example Merge Object SOP from session 1 (PID 6088) by session 2 (PID 91256) for example.

Thank you.

I can't give you the specifics, but a long time ago I remember reading about hacking (I think) the Unix SOP to do this very thing. Maybe one of the Old School Wizards on here remembers this?

I'm sure you could also do it with Python SOPs and share data through the sockets library.

Can be done using RPC: https://www.sidefx.com/docs/houdini/hom/rpc.html [www.sidefx.com]