The initiative it takes to back-engineer the .Net frame work, while admirable, is a wee bit misguided, i'd say. You have to understand what's really at play here.
The whole idea of chasing after a proprietary standard like .Net (and treating the development process like some open source cat-and-mouse game) is pointless. It accomplishes nothing but an at-best "acceptable" knock-off.
If Microsoft doesn't want the .Net framework available on other platforms, they're not going to make it available. Then on the other hand, if they find it's to their benefit to do so, they will make it available. It's as simple as that. Suppose you actually make it to the point where you have an equivalent framework to offer. Surprise, Microsoft releases .Net for Unix, and the entire effort is null and void. Your pride and joy is now a footnote, and a deprecated one at that. Realistically, how many people are going to feel sorry for someone who's stance reads, "Damn those fuckers in Redmond for making their framework available in Unix!" ?
Unfortunately, Miguel seems to have a fairly long track record with this sort of Microsoft-chasing. You can run along and play catch-up all you like with other technologies, but, it'll be just like it is with Gnome ---- With Gnome, you're guaranteed nothing better than a perpetual second place finish. Gnome amounts to a Windows wanna-be, instead of a Windows-killer, when it didn't have to be that way. Miguel made it that way.
Look...If you HAVE the talent to do something better, for God's sake, do it. Don't waste your time (and other peoples time) churning out flea market knock-offs of worthwhile products. I'm certainly no fan of Microsoft..I just call it like I see it. .Net needs not the taint of open-source muckery.