Wikipedia today officially adopted peer-to-peer networking to help power the video displayed on its site. Why? Cost.

"One potential problem with increased video usage on the Wikimedia sites is that video is many times more costly to distribute than text and images that make up Wikipedia articles today," said today's announcement. "Eventually bandwidth costs could saturate the foundation budget or leave less resources for other projects and programs."

So Wikipedia has partnered with the P2P-Next consortium, a group of European researchers whose work is funded with a €19 million EU grant. That work has finally produced a new version of the group's "Swarmplayer" that's almost ready for public consumption. Firefox (Windows, Mac, Ubuntu) users can download the beta Swarmplayer 2.0 plugin, which grabs Wikipedia video from other peers (and distributes it to others; be aware of this if on a low-bandwidth or capped connection). An IE plugin will be available soon.

Javascript on Wikipedia's site identifies whether Swarmplayer is installed. If not, the video is streamed directly from the server; if so, a .torrent file is passed to Swarmplayer, which downloads the video from other users on the 'Net. The setup also includes HTTP fallback should BitTorrent prove too slow.

But this isn't traditional BitTorrent downloading. Swarmplayer's key innovation has been its focus on P2P streaming, eliminating one of the key bottlenecks that originally made P2P distribution a poor substitute for server-based streaming. BitTorrent distribution sends blocks of a file out-of-order, which is no problem for a download; once all blocks are received and properly assembled, the final result is identical to the original file. But for streaming, the initial pieces have to be in place before viewing can even begin.

Swarmplayer handles this by using a hybrid HTTP/BitTorrent model that can grab the first part of a file from a Wikimedia server (HTTP) while filling in all the later blocks using BitTorrent.

The P2P-Next team's goal is nothing less than crafting a replacement for over-the-air television, one which makes distribution so cheap that every "broadcaster" in the world starts using it—and extends their reach to the whole planet.

Back in 2008, when we interviewed the scientific technical director for P2P-Next, Dutch academic Johan Pouwelse, he told us that a more immediate dream was for his work to power a site like Wikipedia. The dream has now come true, though the project currently remains "experimental" at Wikipedia.

Even if you don't want your computer to upload anything, the Wikipedia folks still prefer that you give Swarmplayer a try because it "helps distribute load by playing the video from the P2P network and the local cache on subsequent views." Even if you don't share, you're still helping to reduce server load.