phalanger
Phalanger is PHP 5.4 compiler and runtime for .NET Framework.
Introducing full-featured PHP 5.4 runtime & compiler for .NET/Mono frameworks. Phalanger is an open-source implementation of PHP, compatible with the vast array of existing PHP code. In addition, Phalanger gives PHP application developers a lot of new possibilities; it improves the performance, allows them to use modern environments, and takes advantage of seamless .NET integration.