Guardian
The Cosmic Force
https://www.torproject.org/docs/tor-doc-relay.html.en
"The Tor network relies on volunteers to donate bandwidth. The more people who run relays, the faster the Tor network will be. If you have at least 20 kilobytes/s each way, please help out Tor by configuring your Tor to be a relay too. We have many features that make Tor relays easy and convenient, including rate limiting for bandwidth, exit policies so you can limit your exposure to abuse complaints, and support for dynamic IP addresses.
You can run a Tor relay on pretty much any operating system. Tor relays work best on Linux, OS X Tiger or later, FreeBSD 5.x+, NetBSD 5.x+, and Windows Server 2003 or later. "
"The Tor network relies on volunteers to donate bandwidth. The more people who run relays, the faster the Tor network will be. If you have at least 20 kilobytes/s each way, please help out Tor by configuring your Tor to be a relay too. We have many features that make Tor relays easy and convenient, including rate limiting for bandwidth, exit policies so you can limit your exposure to abuse complaints, and support for dynamic IP addresses.
You can run a Tor relay on pretty much any operating system. Tor relays work best on Linux, OS X Tiger or later, FreeBSD 5.x+, NetBSD 5.x+, and Windows Server 2003 or later. "