The custom Bio::Neos overlay to store any modifications to ebuilds that we need for the office, or any custom ebuilds that we create.
More recent versions of Portage allows you to add additional repositories by
adding a config file in /etc/portage/repos.conf. Here's an example:
[bioneos-overlay]
location = /var/db/repos/bioneos
sync-type = git
sync-uri = git://github.com/bioneos/bioneos-overlay.git
auto-sync = yes
After creating this file run emerge --sync bioneos-overlay