javascript torrent client primarily for chrome web store
https://chrome.google.com/webstore/detail/jstorrent/anhdpjpojoipgpmfanmedjghaligalgb
Sorry, the source code has been removed from github for now due to licensing issues (I worked on it while at former employer)
The Chrome 31 based rewrite is in the "fresh" branch.
https://google.com/+jstorrent (Official Google+ Page)
https://twitter.com/jstorrent (follow to show your support for a rewrite)