Gentoolkit

gentoolkit - Gentoolkit contains a whole bunch of useful tools to help you manage your packages and keep track of what is going on in your system

The tools in gentoolkit are
 * equery
 * euse
 * revdep-rebuild
 * glsa-check

All the above tools have been dedicated a page to themselves, please see that page for more info.

Find more info on gentoolkit on [| Gentoo-wiki]