PPAs or Personal Package Archives are basically software repositories that are used by Ubuntu systems…
Ubuntu Remote Desktop with X2Go
This tutorial explains the installation and usage of X2Go on Ubuntu. X2Go is a remote desktop application to access X-Desktop enviroments over a network connection, it is well suited for low bandwidth connections, has support for sound with PulseAudio and allows desktop sharing. The application has two parts, the x2goclient for the client side and x2goserver (which has to be installed on the desktop system that shall be accessed). The X2Go client software is available for Windows, Mac OS X and Linux.