Tools for format and error checking in your programming language

Lints and Hints: What tools are available for checking and correcting the conventions, style and common errors in my language (lint tools), and are there tools that can automatically fix them (hint tools)?

This is a follow-up to a comment posted on Is there a place for automated code reviews?

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

Let's list a few tools that people can use to address easy and common issues in their code before they ask their questions, and that can help reviewers gather "easy" points to mention in their CR answers...:

• Bash (and other shells)
• C, C++ also C specific
• C#
• Delphi
• HTML, XHTML, CSS
• Go
• Java
• JavaScript
• jQuery
• JSON
• Lisp
• Lua
• MongoDB
• Objective-C
• Perl
• PHP
• Python
• Regex
• Ruby
• Scala
• SQL
• Swift
• VB.NET
• VB6 and VBA
• XML

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.