How to compile universal binary with 2 architectures o Mac OS X?

If i make a project with XCode i can compile it to both 32bit and 64bit. Is it possible to compile Apa开发者_如何学Cche this way too? So it will work on both architectures? Make it a universal binary with these 2 architectures?

Yes, just build the two architectures and then use lipo to combine them into a fat binary.