PVP.net

PVP.net is the front-end interface for the player versus player aspect of League of Legends.

Functionality
PVP.net is a platform for League of Legends to launch from. It allows you to add friends, check the League of Legends store, and join chat rooms. PVP.net can be considered a seperate entity from the actual game but the two are linked and can not be used separately.

Adobe Air
PVP.net uses a "runtime environment" called Adobe Air. You are required to have the latest version of Adobe Air to open PVP.net and play League of Legends. The League of Legends launcher is set to download and install the latest version of Adobe Air, but some players find they must install Adobe Air manually from the Adobe download site.

Trivia

 * If you type the link PVP.net and press enter you will be redirected to the Official Web Page.