Nomachine recently released a new major version (3.3.0), which did not introduce many new features, but fixed some bugs (some keys did not work here on my french keyboard for example), and generally feels "snappier" (in my opinion of course, test and check it for yourself ;) ). It is available in portage for both free server edition (binary only, 2 concurrent connections), and for freenx (open-source, no connections limit).

For some time an alternative client/server from 2X has been available in portage, as net-misc/nxclient-2xterminalserver and net-misc/nxserver-2xterminalserver. Based on old NX 1.5, it provided both a GPL client (missing the > 2.0.0 NX features though) and a working server close to Nomachine one. However it never really got any updates since it was made available. Upstream closed down the website, the client needs fixes for gcc 4.3 and --as-needed, does not work well with current NX servers, the server is still based on old NX code (and is probably vulnerable to some xorg security issuse), so this is last rites time for both of them. They will still be available in the NX overlay if you need them.

Open-source alternatives are availble in portage: net-misc/qtnx for client, net-misc/nxserver-freenx for server.

Now I promised to talk about newer NX systems right? A new bug report was recently opened on x2go, a "server based computing environment" which uses NX technology but is not a clone of current nxclient/nxserver. Nice thing is everything is open-source, including the client (ebuild for it already works). Now some work is needed before there is a x2goserver package in portage, but that will certainly make a nice alternative to current NX servers available. If you already use it, don't hesitate to come and comment on the bug!

Note to myself: I really need to write some documentation on all of these one day...