Phalanger – the PHP Language Compiler for .NET Framework: The idea of working with this is enough to make your head explode.
[…] the object model in Phalanger enables to combine PHP objects with the .NET ones. It is possible to use a class written in PHP from a .NET application or even to import a .NET class (written for example in C# or Visual Basic .NET) into PHP scripts provided that this class respects the PHP object model implemented in the Phalanger. The Phalanger is the only existing PHP compiler which produces .NET Framework MSIL bytecode.
Vie SitePoint, who called it “PHP Sharp.”