How about using universal binaries that not only allows an app run in Haiku, but also on other OS’es? The developer would be able to compile a single binary that runs on Haiku, OS X, Ubuntu and windows. I think it would be nice to have a app on a USB-stick and be able to run it on any computer regardles of OS. Also if there was a devtool that would allow this then many developers would use Haiku. Is this suggestion realistic at all? And if it is possible, how hard would it be to make this happen?
Yeah, there’s this neat thing called “Java” 
Actually, even Java apps barely run cross-platform - in some cases they use platform-specific APIs or rely on platform-specific bugs/features.
Frankly, I don’t see this as a realistic feature of Haiku specifically. If you’re referring to “fat binaries” then I think this is a non-starter as it would probably require modifications to other OS platforms as well.
Haiku’s Java port stalled in the same way as previous BeOS projects of the same kind. Realistically, as with other projects that require someone pretty technical to give it a lot of attention, Haiku doesn’t have the man-power to make it happen.
“Third party opportunity” is what JLG used to say at this point, but it was really always a euphemism. These aren’t opportunities, they’re dependencies.
I wasn’t suggesting that Java was available yet - I was only referring to the concept of one-binary-runs-everywhere which was supposedly realized with Java.