[gentoo-server] Binary "mirror" server?

[Jason Qualkenbush]

I have an internal mirror for rsync and distfiles.  Now my users tell me
that we can setup a build server and install the precompiled binaries
off of that.  From what they were talking about, it sounded like a
mirror, but serving compiled packages.  Is anyone doing this?  I can't
find information on this, but that's probably because I don't really
even know what to look for.  Is there a document on this somewhere?

-Jason