via Rob Howard: It looks like a group has created a PHP Compiler for the .NET Framework. It seems like it could be a pretty useful tool if you need to create both PHP and ASP.NET Web applications. In the comments of Rob's post and in response to Rob's question on whether it's built on top of the HttpRuntime, a developer on the project indicated that it is, in fact, built on top of the HttpRuntime. This should make it easy to integrate PHP and ASP.NET applications; I'm definitely going to be checking it out.