piwik is an open source (GPL license) web analytics software. It gives interesting reports on your website visitors, your popular pages, the search engines keywords they used, the language they speak… and so much more.
Piwik - description of the software, why is it better than the competition, screenshots
piwik aims to be an open source alternative to Google Analytics.
1. Open APIs
2. Plugins Architecture
3. Data abstraction layer
4. Customizable dashboard
5. Innovative User Interface