You can survives disconnects even with xlib, I think the abort is just the default behavior.
Emacs is the one program I know of that can actually do this. It can pop up frames (Emacs lingo for windows) on multiple displays at the same time and even mix tty and X11 frames. The Emacs session survives connection loss fine, frames on other displays continue working and you can reconnect if desired.
The one caveat is that Gtk used to have a bug that caused it to uncontrollably abort on connection loss but I build my Emacs with --without-x-toolkit (so it uses raw xlib, no toolkit) and that configuration has always been robust and performant. If I remember correctly the Gtk bug might be fixed now too.
Emacs is the one program I know of that can actually do this. It can pop up frames (Emacs lingo for windows) on multiple displays at the same time and even mix tty and X11 frames. The Emacs session survives connection loss fine, frames on other displays continue working and you can reconnect if desired.
The one caveat is that Gtk used to have a bug that caused it to uncontrollably abort on connection loss but I build my Emacs with --without-x-toolkit (so it uses raw xlib, no toolkit) and that configuration has always been robust and performant. If I remember correctly the Gtk bug might be fixed now too.