The FSF warns (again) against Mono

mono/.net legal issues are the same with other software.
The real issue is that mono a huge technical kludge driven by MS (commercially too).
That's fairly enough to stay far away from it, period.
Hope debian and canonical won't force upon users such a controversial bloat (canonical plz). Each time I install a GNU/Linux Ubuntu, I must remove mono: tomboy is useless as my users don't give a damn of its use (same fate for the sainer sticky notes), and gthumb does the job instead of fspot, heard there are other image viewers, even ligther than gthumb and which do the job too.
The only real interest of mono is to be what is wine for win32/64, just a compatibility layer.