Open-Source "Ratings & Recommendations" Software?

The Llama King asks: "Our group has an interesting idea for being able to rate different items, then receiving preferences for similar items, a feature found at sites such as NetFlix and Amazon. Unfortunately, we have big ideas and a small budget. I've searched high and low for an open-source version of this kind of algorithm, with no success. Are there any out there worth compiling?" Update: 05/16 10:30PM EDT by C :As it turns out, Jamie has some words on the subject, click below for more.

In an email from co-editor, Jamie:

"I researched this stuff for a possible project some years back. Not much has changed.

There isn't any open-source code out there that I know of, but, people have been writing masters' theses and dissertations about it for several years now. They can go search the literature if they're really interested. But there isn't just a perl module you can install to get this stuff...yet.

You should probably try these search terms:

• 'recommender system'
• 'recommendation system'

'FireFly' is another one -- that was the name of some (fairly successful) recommendation software which was purchased by our favorite innovator, Microsoft, three years ago and repackaged as (surprise!) 'Passport.'

[And for those interested]...here's a promising link .