Because early adopters of the website were prominent Microsoft developers. Such as Jon Skeet. This caused network effects. To suggest just because a door is opened that every developer has an equal chance of walking through is absurd. This is not evidence that the general software community wants or needs c# more than any other thing. For many developers more traditional channels of q and a are still popular, such as mailing lists.
Jon Skeet is a Google developer. Well early Git adopters were Linux developers. Does it mean that GitHub is not really mainstream apart from a narrow group of people?
Assuming this isn't supposed to be rhetorical - yes, it works pretty well in fact. Windows's bizarrely ropey FS performance means it's a bit slower, but in general the experience is basically the same as using it under OS X. SourceTree/git gui/gitk are work the same.
It may be now (I'll take your word for it), but for the longest time, "windows support" was one of the only selling points anybody could provide for choosing mercurial over git (the other being some people prefer mercurial's branching/tagging to git's).
So, if git didn't work fine on windows for a long time, there would be plenty of time for network effects to entrench github as a non-windows site, and indeed that is the case. Github is where you'll find a lot of javascript, trendy open source projects, and even os x apps, but not so much windows stuff.
Open source on Windows (and thus github usage) in general seems to be something of a second class citizen. There's Cygwin of course which brings you a lot of the open source tools, but it's far more common for Windows apps to be closed source it seems. Linux of course due to its nature tends to favor open source apps quite heavily, but it would be interesting to compare how many apps are closed vs. open on OS X as compared to Windows.
So? What percentage of those were (and is) in StackOverflow?
Compared to whole languages communities, for languages like PHP, Java, etc (and .NET), the number of "people who follow Spolsky and started using SO because of that" is miniscule. A statistical noise at best.
It's kind of like how HN was initially very programming/computer science/lisp (?) centric in its early days (at least it seemed that way to me) primarily because of the people who read pgs essays and were interested in start-ups, etc.
That is of course a perfectly valid question and I'm sorry that you got down-voted for asking it. Indeed it was founded by Microsoft technology enthusiasts (Spolsky et.al.) and implemented with Microsoft technology stack. Possibly for these reasons it was (initially) populated heavily with .NET related questions.
> How can an open free Q&A site be concentrated on something?
Very easily. For instance, if there was one toolset that either had worse user-facing documentation or a higher proportion of users who were bad at extracting solutions to specific challenges from general purpose documentation (perhaps because of mandatory use at the kind of places that employ such users), then one would expect that an open, free Q&A site with no deliberate focus would disproportionately end up serving that toolset.
There's a multitude of other ways such a Q&A site could end up with a skewed pool compared to overall use, too, that's just one example.
I was one of the first few hundred users and it was entirely .net/C# questions around this. This was mostly due to Jeff Atwood (at the time) visibility in that community - so it had a vast headstart, things have changed since then but that is how it started (well both Joel and Jeff were slightly more visible in the MS communities).
