BitTorrent story

[bouche]

Note: Linking to NYTimes sucks. You need to login to read so I copied it here.

Apparantly, the founder of Valve Software (Half-Life, Half-life 2)- Gabe Newell - is looking at this guy to help build a distibution network for their games as well.

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File Sharing's New Face

By SETH SCHIESEL

Published: February 12, 2004

SEATTLE

AFTER working for a parade of doomed dot-com startups, a young programmer named Bram Cohen finally got tired of failure.

"I decided I finally wanted to work on a project that people would actually use, would actually work and would actually be fun," he recalled.

Three years later, Mr. Cohen, 28, has emerged as the face of the next wave of Internet file sharing. If Napster started the first generation of file-sharing, and services like Kazaa represented the second, then the system developed by Mr. Cohen, known as BitTorrent, may well be leading the third. Firm numbers are difficult to come by, but it appears that the BitTorrent software has been downloaded more than 10 million times.

And just as earlier forms of file-sharing seem to be waning in popularity under legal pressure from the music industry, new technologies like BitTorrent are making it easier than ever to share and distribute the huge files used for video. One site alone, suprnova.org, routinely offers hundreds of television programs, recent movies and copyrighted software programs. The movie industry, among others, has taken notice.

What Mr. Cohen has created, however, seems beyond his control. And when he was developing the system, he said, widespread copyright infringement was not what he had in mind.

Rather, he was intrigued by a problem familiar to many Internet users and felt acutely by friends who were trading music online legally: the excruciating wait while files were being downloaded.

"Obviously their problem was not enough bandwidth to meet demand," Mr. Cohen said in an interview at a Mexican restaurant near his home in Seattle. "It seemed pretty clear to me that there is a lot of bandwidth out there, but it's not being used properly. There's all of this upload capacity that people aren't using."

That was the essential insight behind BitTorrent. Under older file-sharing systems like Napster and Kazaa, only a small subset of users actually share files with the world. Most users simply download, or leech, in cyberspace parlance.

BitTorrent, however, uses what could be called a Golden Rule principle: the faster you upload, the faster you are allowed to download. BitTorrent cuts up files into many little pieces, and as soon as a user has a piece, they immediately start uploading that piece to other users. So almost all of the people who are sharing a given file are simultaneously uploading and downloading pieces of the same file (unless their downloading is complete).

The practical implication is that the BitTorrent system makes it easy to distribute very large files to large numbers of people while placing minimal bandwidth requirements on the original "seeder." That is because everyone who wants the file is sharing with one another, rather than downloading from a central source. A separate file-sharing network known as eDonkey uses a similar system.

For Mr. Cohen, BitTorrent was always about exercising his brain rather than trying to fatten his wallet. Unlike many other file-sharing programs, BitTorrent is both free and open-source, which means that those with enough technical know-how can incorporate Mr. Cohen's code into their own programs.

While writing the software, "I lived on savings for a while and then I lived off credit cards, you know, using those zero percent introductory rates to use one credit card to pay off the previous card," Mr. Cohen said.

The first usable version of BitTorrent appeared in October 2002, but the system needed a lot of fine-tuning. Luckily for Mr. Cohen, he was living in the Bay Area at the time and his project had attracted the attention of John Gilmore, the free-software entrepreneur, who had also been one of the first employees at Sun Microsystems. Mr. Gilmore ended up helping Mr. Cohen with some of his living expenses while he finished the system.

"Part of what matters to me about this is that it makes it possible for people with limited bandwidth to supply very popular files," Mr. Gilmore said in a telephone interview. "It means that if you are a small software developer you can put up a package, and if it turns out that millions of people want it, they can get it from each other in an automated way."

BitTorrent really started to take off in early 2003 when it was used to distribute a new version of Linux and fans of Japanese anime started relying on it to share cartoons.