Fabien Potencier has written up a post detailing a PEAR channel server manager he's developed, Pirum.

Pirum lets you setup PEAR channel servers in a matter of minutes. Pirum is best suited when you want to create small PEAR channels for a few packages written by a few developers. Pirum consists of just one file, a command line tool, written in PHP. There is no external dependencies, no not need for a database, no need to setup credentials, and nothing need to be installed or configured.

All you need to do to get the tool is download the pirum file and go. It includes features like per-channel HTML pages and Atmos feed release tracking along with several other standard PEAR channel features.

There's already been one project that's made the swtich - PHP_Depend.