1. ESLint. http://eslint.org/. ESLint. http://eslint.org/.
2. JSHint. http://jshint.com/. JSHint. http://jshint.com/.
3. JSLint. http://www.jslint.com/. JSLint. http://www.jslint.com/.
4. The Closure Linter enforces the guidelines set by Google. https://code.google.com/p/closure-linter/. The Closure Linter enforces the guidelines set by Google. https://code.google.com/p/closure-linter/.
5. ECMAScript language specification 5.1 edition June 2011. ECMAScript language specification 5.1 edition June 2011.