And before you point out that Mono is not Microsoft-specific, my reasonable fear is that if Mono ever gets too effective, Microsoft can pull the rug out from under it at any point with patent claims on all sorts of pieces to .NET that might have found their way into Mono.

I'm happily only going to be working with computers until the end of May, 2015.

My reasonable assumption is that IIS will be unable to build a reputation as a "secure, stable, non-virus prone webserver" before it no longer matters to me (i.e. before the end of May 2015). Hence, it is in Microsoft's interest that Mono be as successful as it can be. Otherwise, .Net applications will only run on that part of the web market-share that runs IIS (never more than 30%). Another reasonable assumption of mine is that Microsoft doesn't want to be in any market where it has less than 1/3 the pie. So, while I accept your supposition that MSFT will ultimately find a way to kill Mono, I believe that MSFT will not be motivated to do such a thing until they can get enough people to trust IIS - which, as I say, I anticipate being sometime after May, 2015 :-)

Their mission has always been to own every computing market they enter. Thinking that will somehow change over the next x years is a very bad assumption.

If Mono is successful, people will use .Net if only because of the legions of Visual Basic programmers out there. Yes, Microsoft made its money selling DOS and then Windows. But, the reason DOS and Windows *had* to be sold with every computer was/is the tools and applications written for that platform. They need .net to take off, (so much so that they are even providing a port for FreeBSD themselves). At this point getting more people to use .net is what the game is all about.

As big a fan of Linux as I am, it will not be until I am happily removed for IT work that Microsoft ever loses any significant amount of marketshare on the desktop. That alone will keep the Windows revenue rolling while they wait for .net to become a standard. And it will, like it or not. We all like to bash Microsoft, but the plain and simple truth is that they won the software dev tool and application market almost fair and square (Word was better than WordPerfect, Access better than Xbase, Excel better than Lotus, Visual Studio better - in the sense that it worked better with Windows - than anyone else's tools, etc.)

There will, of course, always be niches where Microsoft tools and Windows are not used, but as has always been the case, they will be the small exceptions.

emphasis mine
...it is what Microsoft has done with core markets (eg office) once it hits market saturation.

We disagree that .net will reach market saturation, or perhaps how long it will take until it does. But your statement above I could have written.

AFA OO - something else taking share from Microsoft Office, we absolutely disagree if your position is that it will take less than 11 years for that to happen.

I hope we still have a way to exchange views in 11 years. It'll be interesting to see who's right. :-)