Differences between Piwik and G analytics

Hello, I want to know what are the main advantages of Piwik over Google Analytics?!

Thanks.
Igrik

For me :

  • Piwik is free in all meaning of the word.
  • It's installed on our own hosting so the stats collector can't go offline while your site still receive visitors.
  • You own your stat database and nobody else can have access to it.
  • It work with plugin so we can have all the functionalities we want and only the functionalities we want.
What else ?

after I installed piwik, the interface of statistics very pleased me, for this separate thank you

GA is good but piwik the best, because we can extend functionality in piwik. GA is limited.