Hello, > I am been using Gtk# for a GUI hoping to make a cross-platform program. > But I just realized that Gtk doesn't work on Macs, does it? Gtk# works on Macs just fine. See the screenshot of Monodoc and MonoDevelop running on MacOS X. In the future, there will be a native port of Gtk+ to use CoreGraphics and AppearanceManager so the X dependency will be dropped. Miguel