A great library is almost useless without documentation. PEAR has over 300 packages, automatically generated API documentation and a manual. The PEAR manual (the one you are reading) shall provide an overview on the packages and instructions about how to use them, and give an understanding about the classes in a package, and their methods. Further information about them can looked up in the API docs.
With the amount of packages PEAR provides, it's hard to keep track of the state of documentation of the packages - a tool to track this was needed. QA_Peardoc_Coverage is its incarnation.
QA_Peardoc_Coverage uses a CVS checkout of PEAR and PEARDOC to find out which packages are documented, which classes and method are mentioned in the docs, and which developers do a good job in documenting their code.