Yesterday, Google released their open-source passive web application security assessment tool called ratproxy.
This utility, developed by our information security engineering team, is designed to transparently analyze legitimate, browser-driven interactions with a tested web property and automatically pinpoint, annotate, and prioritize potential flaws or areas of concern.
The proxy analyzes problems such as cross-site script inclusion [...]

Niels Provos mentioned it at today’s Web 2.0 Security and Privacy workshop, and somehow everyone I knew missed Google’s official announcement last week of the safe browsing diagnostic page.
So what type of information is given back to the user?

What is the current listing status for [the site in question]? [...]