On his blog today, Stefan Mischook compares two of the popular component libraries out there - PEAR and the Zend Framework (yes, it can be considered a grouping of components too).

Now that the Zend Framework is ready for 'prime time', I’ve been considering the Pear framework with regards to how it now fits in the PHP world.

He suggests that not could both be considered component libraries, but might also both be frameworks (based on a definition that a framework is a "consistent set of components that are designed to work together in a unified manner"). He also asks about the need for something like PEAR now that the Zend Framework has come along, getting Jonathan Lebensold's opinion too.