Windows development using Objective-C

With respect to your first question, I don't know if anyone is seriously doing development on windows with Objective-C, but there may be, though those numbers would probably be less than those doing serious work with a language like whitespace.

Secondly, you would need, at a minimum the objective-c runtime. There are two runtimes, NeXT's (now Apple's) runtime, and the GNU Objective-C runtime. They are not compatible. If you are on a non-NeXT and non-Apple platform, such as windows, you have no choice, GNU runtime only.

Objective-C is a superset of C, and yes you can use the Win32 API if you so desire directly in your objective-c code. As well, you would only get garbage collection if you use a conservative collector, and it ties in with the libraries you're using. In short: No.

What GCC has is support for the objective-c language, and runtime, no standard library. What the GNU objc runtime provides you with in terms of a standard library, is two objects: Object, and NXConstantString class, which is needed to support the @"" syntax. Object is merely a base class. Not very useful, eh? This is why frameworks like Cocotron and GNUstep exist — to give you access to an implementation of OPENSTEP/Cocoa.

Regarding pitfalls or traps, yeah: Your application, even using Cocotron or GNUstep may never be portable to the Mac for instance, or you may get bit by things like typed selectors in the GNU objc runtime, or a plethora of other problems. Let me finish answering this by posing another question: What pitfalls or traps might you run into targeting .NET? I'm sure some if not most of those apply in this case too. Standard pitfalls and traps apply.

I hope this helps.

There is no mature solution yet. If you develop the solution itself, you can do it anyway. But if you're not, it's not the time.

For compiler tools, there is LLVM/Clang which are open-source under BSD license.The compiler is sponsored by Apple, so it compiles Objective-C completely, and is becoming primary compiler for Apple. So compiler is no problem anymore.

Problem is runtime environment library. Objective-C language is depends it's runtime to execute. The runtime defines all behavior of object system and some more. Runtime environment library is core system and different with framework library like Cocoa or Quartz. in .NET, it's CRE, not .NET framework class library.Without runtime, program cannot be executed like .NET program executed on Windows without .NET runtime.

For more details, check this conversation:http://lists.cs.uiuc.edu/pipermail/cfe-dev/2010-January/007593.html