Kiln, Fog Creek's old Git/Mercurial hosting environment, had major components written in F#. Those components honestly were probably the only genuinely bug-free

Kiln, Fog Creek's old Git/Mercurial hosting environment, had major components written in F#. Those components honestly were probably the only genuinely bug-free parts of the code base (though I think that had as much to do with developers self-selecting to work on those areas as it did to do with using F# as such).