Piwik
Piwik is an open source real-time web analytics application. Piwik aims to be an open source alternative to Google Analytics.
Piwik provides detailed reports on your website and its visitors, including the search engines and keywords used, the languages spoken, which pages are popular, the files downloaded, and so much more. Piwik is the leading open source web analytics software, used by more than 100,000 websites.
-Piwik developer