WinForms vs GtkSharp with Mono

Question

When developing with Mono for an app to be run on Windows and Mac OSX (and maybe Linux) which would you suggest, WinForms or GtkSharp for the GUI and why?

Answer 1

GtkSharp requires X11 on Mac OS X. Mac users will find that off-putting. I haven't tried Winforms on OS X, but mono's Linux winforms support was pretty immature (buggy) and slow. I don't think there is a mature .net GUI toolkit for OS X at this point, at least nothing at the level of Swing or SWT.