Bitblinder was an open source software program that allows users to share bandwidth and IP addresses in order to anonymously download torrents and browse the internet. It was first released in June 2009. It was developed by Josh Albrecht and Matthew Kaniaris of Innominet. The software is based on the principles that Tor

Tor (anonymity network)

Tor is a system intended to enable online anonymity. Tor client software routes Internet traffic through a worldwide volunteer network of servers in order to conceal a user's location or usage from someone conducting network surveillance or traffic analysis...

 uses to create anonymity but was designed to be faster and encourage file sharing in addition to anonymous browsing. It currently comes bundled with an anonymous browser based on Mozilla Firefox

Mozilla Firefox

Mozilla Firefox is a free and open source web browser descended from the Mozilla Application Suite and managed by Mozilla Corporation. , Firefox is the second most widely used browser, with approximately 25% of worldwide usage share of web browsers...

 and an anonymous BitTorrent client based on BitTornado

BitTornado

BitTornado is a free BitTorrent client for transfer of computer files over networks, including the Internet. It is developed by John Hoffman, who also created its predecessor, Shad0w's Experimental Client...

.

BitBlinder now appears to be defunct as its web page and software client are no longer functional.