Usually this means iOS and the ARM processor type but RoboVM is also capable of generating code for Mac OS X and Linux running on x86 CPUs. [0]
There are several forks of the latest open-source version of RoboVM. This one in particular is targeting desktop/server usage:
https://github.com/ashleyj/aura
See also: https://news.ycombinator.com/item?id=7579737
[0] http://docs.robovm.com/advanced-topics/compilation.html