At NeoSmart Technologies, we have a special affinity for ecosystems running both Windows and *nix in unison, each doing things they excel at. Half of this website is running ASP.NET MVC under IIS 8.0, while the other half is running under nginx on FreeBSD, everything behind an nginx reverse proxy. Windows likes to make things easy for users by being a primarily case-insensitive platform, both when it comes to the local filesystem and the web. FreeBSD and Linux on the other hand, like most of the unix world1 are explicitly and unapologetically case-sensitive.
On the one-hand, IIS defaulting to case-insensitive URL routing means that your users are far less likely to a see a 404 “Page not found” error as a result of a fat-fingered or mangled URL (which as we all know can be the fault of either the user or the developer), but it also means that when Google’s spiders and ‘bots come around looking to index your content, you’re likely to wind up penalized for having duplicate content. The web itself is officially case-insensitive, and technically both example.com/something and example.com/Something are completely separate, unique, and independent URLs that despite all semantical similarities share nothing in common (though you’d be mad to actually host different content on URLs differing only in spelling).
Welcome SeoRedirect, part of NeoSmart Technologies’ open-sourced Web Toolkit library, which provides case-sensitive routing for ASP.NET on IIS. With the latest update (freshly pushed!), SeoRedirect also gives you control over which GET parameters are also preserved, because apparently worrying about case-sensitivity alone just isn’t enough.
Mac OS X is a notable exception here, as by default it uses HFS+ in a case-insensitive mode, though an HFS+ implementation w/ case-sensitivity is enabled (but rarely used). ↩