You guessed, I've written a vpop-xmlrpc container for PEAR::Auth.

There's also a new version of the vpop-xmlrpc cgi, which is needed for the Auth container, because the method vpop.auth has recently been added.

PEAR::Auth is a package that provides methods for creating an authentication system using PHP. It currently supports several methods of authentication, including LDAP, plaintext files, RADIUS, and SAMBA password files...