Mufin, a powerful music recommendation engine that actually works, has launched to the public. We last covered the site in early October, when it opened in a restricted private beta.

The site, which uses technology created by the same organization that developed the now-ubiquitous MP3 file format, uses an advanced algorithm to ‘listen to’ songs and identify similar sounding tracks based on over 40 characteristics. Such automated systems are very hard to pull off (which is why Pandora, another music recommendation engine, uses human experts), but in my testing Mufin had fared surprisingly well.

Since we last wrote about it, Mufin has introduced a Facebook widget that allows users to get song recommendations from within their friends’ Facebook profiles. The site has also relased a plugin for iTunes, which generates playlists based on tracks in a user’s library (iTunes Genius does exactly the same thing, but it relies on metadata rather than an analysis of the music file itself).