Once shells have easy-to-use support for sending and receiving data between two sessions running as two users, then maybe we can get rid of shared filesystem di

Once shells have easy-to-use support for sending and receiving data between two sessions running as two users, then maybe we can get rid of shared filesystem directories. I think /tmp is a poor solution even if we are going to use the filesystem for this (some sort of per-user spool makes far more sense), but its value is in its ubiquity.