jHamachi project is a Linux GUI for the Hamachi VPN client.
You still need the hamachi client, which you can get here. Once it is installed, you can download jHamachi and run it by typing java -jar jHamachi.jar.
You need at least Java 1.5. If the client can't connect, check your tun settings. Make sure you followed the instructions in the readme file. In most cases, running tuncfg as superuser should help.