Could you please explain me why I must be interested in some language compiler which runs over .net / mono {given I am not interested in .net / mono}
There's no need. Just ignore it.
When I talk about Rakudo Star with co-workers
Rakudo Star is intended primarily to make it easier for
interested folk to try out Rakudo. Imo the Perl 6 project does not have anything useful to show or tell someone unless they are already interested in Perl 6, are willing to suspend the disbelief that reasonably follows from knowing the project has been in the works for 12 years, and are willing to visit #perl6 on freenode and ask about it with an open mind.
So what have perl6, that others don't?
Right now, to simplify things, I'll say it has nothing. It's a work-in-progress update of Perl. When a production ready version ships, there'll be efforts to create soundbites that describe what Perl 6 has, including what it has that is unique. Until then, I could say it integrates just about
everything, does it right, and does it nicely, and that's what it has that others don't, but no one would believe me, so I'll not do that.
