https://help.ubuntu.com/community/FreeNX
1. sudo apt-get install python-software-properties
2. sudo add-apt-repository ppa:freenx-team
If not working, just manually add
deb http://ppa.launchpad.net/freenx-team/ppa/ubuntu lucid main
deb-src http://ppa.launchpad.net/freenx-team/ppa/ubuntu lucid main
3. sudo apt-get update
4. sudo aptitude install freenx
5. nxsetup script is missing. sudo mv nxsetup /usr/lib/nx/nxsetup
6. sudo chown root:root /usr/lib/nx/nxsetup
7. sudo /usr/lib/nx/nxsetup --install
