Frost

Frost is a Freenet 0.7 client that provides newsgroup-like messaging, private encrypted messages, file upload and download functionality and a file sharing system."

Installation
You can find an ebuild for frost in the sunrise overlay, so get that first. Once you've got the sunrise overlay, simply emerge frost.

Note that frost also depends on the official freenet client.

Last step
After emerge, add yourself to the usergroup

In order to make the new group active for your account run