Looking for Cross Platform Game Development Packages

One of the reasons I discover new stuff that gets added to the various code libraries here is that I'm usually looking for something for myself or a reader. Recently one of the regulars asked for an interesting C++ project to stretch his abilities and we're collaborating on a cross platform strategy game. Cross platform meaning Windows, Linux and iPhone.

Actually the first two will share a common codebase (as much as possible) and the iPhone will be a rewrite in Objective-C. It's tempting to do it all in Objective-C but a bit difficult, especially as I am still learning it and my fellow coder wanted to stretch his C++.

So I've been looking at Cygwin/MinGW (an article is in the works) and trying various packages eg wxwidgets, maybe QT4 and definitely SDL, compiling with G++. If you know of any good Windows/Linux packages or IDEs (eg codeblocks), please let me know. If anything the choice is too much so I'm looking for recommendations and suggestions. Of course a C#/XNA conversion would also be a good thing but there's never enough time.

PS Programming Challenge 16 will be marked this weekend!

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