I'm currently building an application with IUP and it's pain. The only reason I'm using that and not something else is because we need to support Windows XP. Otherwise, use something else. I'd also like to point out that Araq's IUP binding isn't updated for recent versions of IUP, so you'll have to add your own wrappings for more recent functions. Someone wrote another wrapping for IUP in Nim called [niup](https://github.com/dariolah/niup/), but due to my personal weird requirements, I wasn't able to use it.
@PMunch does wxNim support Windows XP? If so, I'd like to use that instead lol