I had read that #twenex (TOPS-20) for the PDP-10 had very slick terminal handling, but I just experienced it -- I was detached from twenex.org for reasons unknown, logged back in and ran a finger and saw that my previous session was still there. A quick logout and ATTACH instead of LOGIN ... reconnected the unexpectedly lost session. No third-party terminal multiplexer required! #retrocomputing like we're in the future.
"I appreciate SDF but it's a general-purpose server and the name doesn't make it obvious that it's about art." - Eugen Rochko