Piwik is downloadable, Free/Libre (GPLv3 licensed) real time web analytics software. It provides you with detailed reports on your website visitors; the search engines and keywords they used, the language they speak, your popular pages, and much more.

Piwik is a free software alternative to Google Analytics, and is already used on more than 320,000 websites.

Piwik is a PHP/MySQL software program that you download and install on your own web server. At the end of the five minute installation process you will be given a JavaScript tracking code. Simply copy and paste this tag to any websites you wish to track (or use an existing plugin to do it automatically for you) and access your analytics reports in real time.

In layman’s terms, you can check out who has been visiting your page, when, how and why. You can create goals and track conversions. You can track unlimited number of websites, and create users with permission to view or administrate one or several websites.

If you don’t speak English, fear not. Piwik is available in more than 40 languages (and growing!).

What makes Piwik unique from the competition:

1. Real Time Web Analytics Reports: in Piwik, reports are generated in real time by default. For high traffic websites, you can choose the frequency at which reports are processed (more info)
2. You Own Your Web Analytics Data: because Piwik is installed on your server, the data is stored in your own database and you can get all of your statistics using the powerful Piwik Analytics API.
   Piwik is a Free Software which can easily be configured to respect your visitors‘ privacy.
3. Modern, Intuitive User Interface: you can fully customize your Dashboard and drag and drop widgets you want to display (take the Piwik tour).
4. Get Additional Features with Plugins: you can add new features and remove the ones you don’t need. You can build your own web analytics plugins or hire a consultant to have your custom feature built in Piwik
5. Vibrant International Open Community of more than 100,000 active users (tracking even more websites!)
6. Advanced Web Analytics Capabilities such as Ecommerce Tracking, Goal Tracking, Campaign Tracking, Custom Variables, Email Reports, and more!

Here is an example of the Real Time Visitor Log showing you all visits, their actions on your site, how they reached your website (which keywords they typed or link they clicked on), Custom Variables, and more!

http://piwik.org/