http://selfproject.eu/
SELF is an international project that aims to provide a platform for the collaborative sharing and creation of open educational and training materials about Free Software and Open Standards.

Spotplex is the only online content aggregation service that dynamically provides an instant, impartial ranking of popular Web content. With Spotplex, Internet users are not required to change their behavior to generate content rankings. By eliminating tagging and voting, Spotplex more accurately reflects what people read most today.
Based on an algorithm-based measuring system that analyzes readers' behavior in real time, Spotplex's popular content rankings come from actual impressions, or "reads". This impartial process gives every blogger a better opportunity to be heard. Spotplex also uses a relative popularity measure by which article reads are measured relative to a site's overall traffic, rather than by volume alone. This evens the playing field so all blogs can compete equally in the Spotplex rankings, regardless of readership size or subject matter.