[Mono-list] how to develop a cross platform solution with Mono

[Sam Carleton]

I have spent many year as a C/C++ programmer and in the last two years
I have been developing in C#.  I seem to like .Net over C++.  I am now
working on my own program that I am going to need to go cross
platform.  The customers are photographers so they want a OSX version.

I am currently working on the beta and it is all in .Net.  I like the
idea of sticking with .Net, but I am having a hard time grasping the
best way to do a unified GUI.  Back in January I used the tool to see
if what I had developed at the time was supported by Mono and I ran
into two issues.  One was the file monitoring functionality was
supported in Linux, not in OSX, which is the core to my program.  The
other problem was the GUI.  Of course everything I am currently doing
is WinForms.  It would seem that the treeview, or at least how I am
using it, is not fully supported by Mono yet.  It makes me wonder
about unified GUI development.  The last thing I want to do is have a
Gtk# for Linux, once I get there, WinForms for Windows, and CocoaSharp
for OSX.

So in the end, my thoughts have been leaning towards punting with .Net
and either using Mozilla's XULRunner and XPCom as the framework, or
using Qt.  I do like C++ development, but I do fully respect the speed
and ease of .Net development, so the question remains:

Is there a way I can develop a unified GUI using Mono that will give
me a rich user interface in both Windows and OSX?

Sam