What Are Overlays?
"Overlays" are package trees for Portage. They contain additional ebuilds for Gentoo. They are maintained by Gentoo developers and projects but distributed separately from the main Portage tree.
Why call it Overlays?
Within Gentoo Linux, users already have one "main" package repository, called the Portage tree. This main repository contains all the software packages (called ebuilds) maintained by Gentoo developers. But users can add additional repositories to the tree that are "layed over" the main tree - hence the name, overlays.
From Gentoo Wiki: Overlay
# Install layman emerge -av layman #(for layman 1.3 and later) # Init config echo PORTDIR_OVERLAY=\"\" > /var/lib/layman/make.conf echo "source /var/lib/layman/make.conf" >> /etc/portage/make.conf # List remote overlays layman -L # Add a overlay layman -a <overlay-name> # Update the specified overlay layman -s <overlay-name>
http://gpo.zugaina.org/ is a website to Search Portages & Overlays.
I want to install git-flow, there is no ebuilds in the offical portage.
So I search it in this website. and find the page http://gpo.zugaina.org/dev-vcs/gitflow is what I need.
There are found items in the page, from different overlay, but the ebuild file is the same, so any one is ok.
Overlay on the right is the overlay name, I choose the overlay
flora, and add it:
layman -a flora layman -s flora
emerge -s gitflow and can install it.