Piwik

Piwik is very simple to use. I adopted Piwik 4 years ago and my client noticed a massive difference with Google Analytics. It's highly customized and I've created some implementation in my apps (you can find one on http://puresourcecode.com/post/piwik-c-tracking-api). The Piwik administration is very powerful and you can find a lot of widget from reporting to geocoding.

Piwik uses PHP and MySQL and for that I must be created a dedicated machine because I'm afraid to mix Windows Server network with. Sometimes is difficult to find why Piwik has a strange behaviour but at the end if you play with the configuration, you'll find a solution (for example if you want to have a statistic for the last year, you must enable this function).

Piwik is a very powerful and customizable application, more competitive with Google Analytics. I'm using it in enterprise environment and the performance has brilliant. Another important thing is with Piwik my clients are very happy and they can use it without problems. You can customize it with your needs and it is easy to implement it in your application. Piwik can read all Google Analytics settings.