kdeenablefinal - Makes kde ebuilds use the enable-final flag, yielding big compilation speedups at the cost of very heavy mem usage
kdexdeltas - Makes kde ebuilds download binary diffs rather than entire new tarballs for every new release
kerberos - Adds [[kerberos ]] support
krb4 - Adds optional kerberos 4 compatibility support
ladcca - Adds Linux Audio Developer's Configuration and Connection API support (LADCCA)
scanner - Adds support for scanner hardware (e.g. build the sane frontend in kdegraphics)
sdl - Adds support for Simple Direct Layer (media library)
selinux - !!internal use only!! Security Enhanced Linux support, this must be set by the [[selinux ]] profile or breakage will occur
session - Adds persistent session support
sharedext - Adds support for building shared extensions in php