Piwik is a downloadable, web analytics software package. It provides detailed reports on your website and its visitors, including the search engines and keywords they used, the language they speak, which pages they like, the files they download… and so much more.
Piwik aims to be an open source alternative to Google Analytics.
Piwik is PHP MySQL software which you download and install on your own webserver. At the end of the 5-minute installation process you will be given a JavaScript tag. Simply copy and paste this tag on websites you wish to track (or use an existing plugin to do it automatically for you).
To learn more about what Piwik offers, check out the list of features page.

How much does Piwik cost?