There are several ways to contribute to something as big as an OS.<p>Right now I'm contributing to Microsoft's coreclr trying to get it to build and run on FreeBSD, because I believe having a wide choice of software and software platforms will indirectly aid the project.<p>If a new project you see doesn't work on your platform, find out why and submit a patch containing your fixes. That will both make it easier for people coming along later and raise awareness of the platform amongst developers.