Following up on a comment posted on http://meta.codereview.stackexchange.com/q/5244/23788

Would a list of static analysis tools help jumpstart this? – h.j.k. 34 mins ago

Let's list a few tools that can help reviewers gather "easy" points to mention on CR questions... and reviewees address "easy" itchy spots in their code, before they post a CR question.

To keep this organized, please post one tool/language per answer; if it's a paid/commercial tool, please mention it. Also please include a link to the website.