The BitTorrent protocol is a peer-to-peer file sharing protocol used for distributing large amounts of data. The big file is broken down into smaller parts and it automatically fetches parts from multiple hosts at once. It also shares the parts you've already downloaded with others, so that everybody shares and benefits.

The technology itself is perfectly legal, but it has been debated if its implementation in connection with copyrighted material or otherwise illegal material makes the issuer of the bittorrent file, as opposed to the copyrighted material itself, liable as an accomplice or infringer.

It is a good way to download Ubuntu iso releases, especially when the regular release sites are slow, since it actually gets faster when there are lots of users downloading and sharing at once.

Here is how you can use BitTorrent in Ubuntu, starting in 10.04 (the instructions might change slightly in each release, but the basic idea is the same).

For this example, I'll be using the Ubuntu 11.04 Desktop ISO - but anything that has a .torrent extension will work following these instructions.

Open up a Web Browser (For more on what Web browsers are available for Ubuntu, take a look at this question,

Then, you'll need to download your .torrent file and save it to disk.

If this is your first time running Transmission (the default BitTorrent client in Ubuntu) then you'll be confronted with the following box - think long and hard if you agree to it

Then you'll need to click the "Open" button and navigate to your .torrent

Sit back and relax while the torrent downloads.

After the download completes, it is often considered good etiquette to continue to seed the file until you reach a 1.00 ratio. Please be aware that if you have a monthly quota many ISPs count uploads against your total bandwidth.