Pantheon

Pantheon is a new lightweight, modular desktop environment primarily written in Vala and GTK+, for the elementary OS project.

Installation
Pantheon currently resides in the elementary overlay. You will first need to ensure you have layman installed. Then you will need to add the elementary overlay.

Next, we need to add the ~arch keyword to allow installation. At the time of writing only is supported. After keywording, Portage will give instructions for all dependent packages that also require a keyword. A list of required keyword changes is supplied below.

You should ensure that X is included in your global USE flags. Beyond that, I've added a list of other necessary USE flags to install pantheon:

Now, you should be able to emerge pantheon:

Minimal installation
The pantheon meta-package pulls in most of the available packages. It might however be wise to start a little smaller. This can be done by emerging just the package and then select the elementary applications you want to give a try:

And then for example just emerge Audience and Pantheon terminal:

Reporting issues
As mentioned in the beginning, the elementary overlay is undergoing rapid development, just like the upstream elementary OS project. This means that things might break, or do not work properly yet. If you discover any issues, or if you want to contribute, just create a new issue on the elementary overlay Github project or contact the [mailto:elementary@vullersmail.nl maintainer].