The Foafing the music

Site URL: http://foafing-the-music.iua.upf.edu

The system has shown the following fatal error when I login the system :

Fatal error: Cannot redeclare array_intersect_key() in /usr/local/share/foafing-the-music/include/General/functions.inc.php on line 26

I have tried to contact them, but I haven't got any reply from them. It seems they don't manage the site these days. If anybody know the current statues of the site, please let me know it. I will appreciate your help.

BTW, I read a paper (FOAFING THE MUSIC: A music recommendation system based on rss feeds and user preferences) about this site. In this paper, the author explains how the music recommendations are generated in the system. At first the system get interests from user's FOAF profile and detect artists and bands. And then, the system select related artists, from artists encountered in the user's FOAF profile and rate results by relevance. The following figure is the recommended artists from artists detected in a user's FOAF profile.
To get the artist's similarities, a focused web crawled has been implemented to look for relationships between artists (Such as: related to, influenced by, followers of, etc) . If the system detects the following artists from the user’s profile: Dogs d’Amour, Social Distortion, The Misfits and The Pogues. Starting from these artists, the system searches for similar artists and for artists influenced by them. Then, it scores them in terms of counting artist occurrences.