This is the beginnings of Stetic, which will eventually be a new GUI designer for GNOME. At the moment, it is just a mostly useless demo of certain bits of Gtk#. To build Stetic you need Mono/MCS head (a recent 1.1.x release is *probably* ok), and the very latest Gtk# (yesterday's snapshot is probably too old). FAQ: Q. "How do I--" A. You can't, it's not implemented yet. Q. "Why does--" A. Because it was just a quick hack. It will be different later. Q. "Can I--" A. No. Q. "But--" A. I'm sorry, which part of "mostly useless" didn't you understand?