Hey guys, just wondering what some of your favorite cross platform SDK's are.

I would like to adhere to iOS, Andriod, Windows Phone, and Windows XP++. Language needs to be able to support client / server (remote) functionality and sockets, so I'm not sure the javascript solutions are appropriate.

So far, I have found Xamarin Studio which fully suits my needs. But it is expensive. Anyone have any great alternatives before I fork out 6 grand a year? I like the idea of one code for all which Xamarin seems to do nicely all three platforms with C# back end.

i've only used appcelerator, but it doesn't support windows afaik.

6k/year is pretty small considering how much time you'll spend on it. that's what, 1-2 weeks of labor? if you like it, i'd go for it.