PHK is a library and application packager. It is a sort of PHP-oriented jar. As such, it allows you to distribute and run a whole application as a single file.
It includes many features and options, such as on-the-fly decompression, Web access restriction, CRC consistency checks, digital signatures, meta-packages, an integrated autoloader, etc. PHK also provides a standard way to display every information about the package, as documentation and license, through an embedded mini-website.