Gentoo - Introduction - Portage

From Kolab wiki

Kolab2/Gentoo is currently not included in the main portage tree but available as a separate project that can be easily integrated as an overlay. The sources for the packages directly originate from the kolab cvs system so it comes with all the advantages and disadvantages of working on the bleeding edge. Consequently the project is currently in a beta stage and stabilization is planned once Kolab-2.2 is released.

There may be a chance that the packages will get included into the main portage tree but this still needs discussion and is currently not forseeable.