FireScope is a Firefox add-on that integrates with Firebug, to extend it with reference material for HTML and CSS. The extension's core functionality is centered around a new Reference panel, which contains a search tool for looking up HTML elements, attributes, and CSS properties.
NVU - Finally! A complete Web Authoring System for Linux Desktop, Microsoft Windows and Macintosh users to rival programs like FrontPage and Dreamweaver. Nvu (pronounced N-view, for a "new view") makes managing a web site a snap. Now anyone can