I'm about to embark upon a rather mammoth project to write a broadcast control system from the ground up. My only real requirement is that is should be cross platform, the code should be able to run on a variety of platforms in particular windows, linux, OS X and Pocket PC with very little change (preferably none).

Until recently I would've used Qt to do this, simply because it seems to tick all the boxes and I know what I'm doing. The only thing I don't seem to be able to do is compile for Pocket PC with Qt, there is Qt Embedded but I don't know of many handhelds actually running Linux that are freely available in the UK.

I'm wondering wether it would be worth starting to learn C# and write it in .NET/Mono or stick with what I know with Qt? As an aside it looks like .NET would be the best way to make Pocket PC apps anyway.