[omail]

I'm not sure why they decided the display should be the server and the programs be the clients. It might be because the other way around is to have one client, the display, access many servers, the programs. That seems even less right to me. (On the other hand, that would make it easier to let a friend over the network look into one of your windows.)

Commercially speaking, X11 was a great success. It is the de facto windowing system for UNIX and UNIX-like systems despite all of the horrors it brings.

[nailer]

Being the defacto windowing system for a platform that has very little desktop market share isn't a great success.

[omail]

Being the defacto windowing system for the most popular operating system family is a great success.

And if you believe Windows is the most popular OS family, then being the defacto windowing system for the second most popular OS family is still a great success.

[nailer]

Actually the defacto windowing system for desktop Unix is OS X's window manager, based on Quartz Compositor.

[omail]

I wasn't referring to desktop systems exclusively, but if I were then you'd have been right.