Broadcatching in its currently proposed form marries the peer-to-peer file sharing program BitTorrent with the increasingly popular RSS (Really Simple Syndication) protocol. BitTorrent is often lumped in the same category as p2p programs like Kazaa, but it features a few fundamental differences that make it ideally suited to broadcatching.
First, BitTorrents algorithm is designed specifically for the transfer of very large files, such as games, movies, or episodes of TV shows. These bulky files are broken down into many small pieces, so users can simultaneously download a torrent of bits from multiple users, which the BT client reassembles into a cohesive whole for the end user to watch, play, or do with as he or she pleases.
Second, BT allows users to download these file packets from each other before the person being downloaded from has even finished their own download of the requested file, thus enabling even faster propagation of popular files through the network. The more people who have a file, the faster that file can be downloaded, which increases the number of people likely to have the file, etc.
BTs ability to rapidly distribute large, popular files means its the perfect venue for sharing timely content like television shows.
Now imagine if your favorite provider of torrent files also provided an RSS feed of those files, and your RSS aggregator had the ability to recognize a torrent file and launch BitTorrent automatically. You could subscribe to the RSS feed provided by that new indie-film producer you just heard about, the network that airs your favorite TV show, the brother-in-law who loves to shoot home movies. You could set this broadcatching system to check for and download new files while you sleep, and wake up to fresh content on your hard drive.