Mono is real
Having been working with .NET for about eighteen months or so now, I have of course been aware of Mono, the open source port of the dot net framework.
Part of the reason for the port (I think) is to lessen the disparity between purely Microsoft technology based developers, and the rest. So for example a Windows C# developer should be able to easily write C# code that'll run on a Linux box.
Part of me has always thought that the whole effort was, to be frank, a bit of a waste of time. My reasoning was how are a group of developers (even the obviously talented Miguel de Icaza) ever going to keep up with the Redmond behemoth's aggresive movement in terms of functionality and innovation?
Perhaps they're going to be ok though. Ok it's perhaps a little thing, but the current ports show that what they've so far accompolished is by no means trivial: check out the current ports which include DasBlog and FlexWiki.
Of course, I only know about these ports because of my involvment with DasBlog through working at Numerica, and subscribing to Clemens Vasters weblog.