refererstats.pl is a Perl program to create statistics about pageviews, separated by generating referer. You can easily identify faked banner clicks, unprofitable advertising partners or see which referer generated how many orders within a day. There is no need to change your web pages, the program runs out of the box. It only parses your Apache log file. Visitors are identified by IP and browser version. Therefore it can not replace much more exact statistics from tracking software. But it works very well just to check the behavier of your visitors separated by referer.