Ruben Vermeersch has released a Zend Framework library for Mollom. From Ruben's release announcement,
Mollom checks your comments and provide CAPTCHAs if it's not 100% sure (about 2% of all comments). This takes the hard work of removing spam out of your hands, with the reassurance that no good content will be blocked..
The Zend Framework is an extensible set of components for building web applications and web services, with more than 7 million downloads and 500 different contributors. Ruben's contribution of the Mollom component allows Zend Framework users to take advantage of Mollom's unique approach to blocking comment and post spam. Thanks Ruben!
— Dries Buytaert