Have you considered Piwik?

http://piwik.org/

Yes, but after evaluating it we decided not to use it. Also, we have a strict no-PHP policy.

Have you decided to not use it only because it's written in PHP or are there any other reasons?

There are other reasons, but PHP is a pretty big one. If we're going to use anything other than Google Analytics, we want to integrate it pretty deeply with our frontend. We were thinking of making a Flask extension that would capture all non-personal information without having to serve analytics code to the client. Also, as far as I know, Piwik does not support DNT.

Piwik actually does support DNT and also can process server logs.

http://piwik.org/privacy/

http://piwik.org/log-analytics/