Because the source code size is too heavy, the binaries (artica-*) sources code are separated from the release package
The web interface is in PHP, so you will find the php code in main package in download section
artica-20091229-fpc.tgz release July Tuesday 23 14:57:47 (22 Mb)artica-20110101-fpc.tgz release July Tuesday 23 14:57:49 (22 Mb)artica-20140101-fpc.tgz release July Tuesday 23 14:57:50 (12 Mb)artica-20081215-fpc.tgz release July Tuesday 23 14:57:45 (18 Mb)