For a handful of good reasons (see Mike's mail), gtk-sharp, the gtk bindings for Mono and .NET, lately chose not to follow the hectic 6 months release plan of both gtk and glib teams but leverage on the almost perfect 2.12.x releases we have now (binding gtk 2.12 and glib 2.16) for a few extra months.
F-Spot, that small photo app everyone like, was, in its SVN/git latests versions, using a lot of the new API additions of gtk-sharp. You probably figured that already if you're following its developments.
So I branched out some of the code I needed from Gtk# svn to 2 new standalone projects, Gtk#Beans and Gio#. Both projects aims to fill the gap between the API mapped by Gtk#2.12 and the capabilities provided by gtk 2.14/glib 2.16.
The code is maintained on gitorious http://gitorious.org/gtk-sharp-beans, http://gitorious.org/gio-sharp and is already usable (and used in f-spot). Feel safe to use them as the API introduced over there will be merged with the fewest possible changes to the next Gtk# release.
2 weeks ago