I haven't really posted about how the WunderCounter works on the back end, but the basic technology is LAMP:
There are lots of scripting languages out there which can do a lot of the same things which Perl does, but Perl has the advantage of CPAN, which is an open source library of thousands of code libraries. Whenever I'm coding something for the WunderCounter, I check CPAN first to see if somebody else has already tried to solve the problem I'm dealing with. In a lot of cases, there's a module on CPAN which solves my problem, thus saving me from reinventing the wheel.
I've even released some of the code with drives the WunderCounter to my CPAN directory. So, for example, if you need to parse out search engines from referring URLs, you can do so quite easily with URI::ParseSearchString::More, which I published a while back. It's the very same module which the WunderCounter uses and it's free for anyone to copy, use, alter, mutilate etc.
I did mention that I'm going to some talks on Git. Having said that, I should say that the WunderCounter is currently kept in a Subversion repository. Subversion is an excellent source control management system. I plan on sticking with it for some time, but Git does a few things better, so I may switch things over to Git eventually. The new WordPress plugin (to be released shortly) is stored in a Git repository on GitHub, so at least some of the WunderCounter source code will be stored in Git.
Hopefully some of you will find that interesting. As a developer, I'm always curious to find out how people manage things on the back end, so I thought I'd share with you a little about how I like to do things.