http://www.lullabot.com/blog/why-not-asp-net

Microsoft has poured huge amounts of energy into building the .NET framework, and it’s fair to say that most Windows software written in the past half a decade or so uses it. Lots of .NET code is being written every day: it is the very opposite of a dead language. It’s got a very robust and feature-rich web framework called ASP.NET, designed to compete with Java as a platform for building web applications. It’s very powerful. As Sasha observes, though, you just don’t hear about new sites being launched on it. Outside of the corporate world, and a handful of select projects like DotNetNuke, it’s a pink unicorn: no one’s ever seen it f’real.