A grep program configured the way I like it.

Turns CSS blocks into [inline] style attributes

JSHint is a community-driven tool to detect errors and potential problems in JavaScript code and to enforce your team's coding conventions. It is very flexible so you can easily adjust it to your particular coding guidelines and the environment you expect your code to execute in.

JSHint is an open-source project that is supported and maintained by the JavaScript developer community. The source code is available on GitHub.

Charles is an HTTP proxy / HTTP monitor / Reverse Proxy that enables a developer to view all of the HTTP and SSL / HTTPS traffic between their machine and the Internet. This includes requests, responses and the HTTP headers (which contain the cookies and caching information).

Dust-Me Selectors is a Firefox extension (for v1.5 or later) that finds unused CSS selectors.