Running cross platform without recompiling

This may soud uttery ridiculous, but What’s to stop me running a Linux project on windows with the mono framework, or a windows gl project on windows. If they can be run across platforms like this, which one is the best out of WindowsGL, Mac or Linux?

IIRC this will work for the WindowsGL project, it should run on mac and linux.
Give it a try?

Not ridiculous but a very good question. Given that the tag line is “Write once, play everywhere.” I’m still trying to understand this. Would welcome anyone with experience to clarify or correct the following;
First choice is DirectX or OpenGL. DirectX set you on a Windows only path so OpenGL offers the prospect for true portability
Although .NET offers the possibility for cross platform operation, it’s not as portable as it could be and portable class libraries aim to address that. I don’t think Monogame, in it’s current form, is set up as a PCL, however I still think/hope it will run ok cross platform without re-compilation using a .NET framework such as mono.
I’ve only briefly looked at the Android, Mac and IOS project templates and am unsure what they are doing but looks like they are getting closer to the native platform and so have very different dependencies (not using mono?) and so need not only recompilation but code changes too.

Well, im focusing on the desktop platforms with gl, but i can’t think on what would be different between platforms. I can only think of keyboard/mouse input