While reading this blog post (in spanish) I came across GoAccess web log analyzer:
GoAccess is an open source real-time web log analyzer and interactive viewer that runs in a terminal in *nix systems or through your browser.
While the terminal output is the default output, it has the capability to generate a complete real-time HTML report (great for analytics, monitoring and data visualization), as well as a JSON, and CSV report.
Even though I haven’t tried it myself, and there are other tools up to the task, I though to share it here as somebody might find it useful. There is a live demo.