Mozilla SeaMonkey: The Mozilla SeaMonkey project includes a Web-browser, email and newsgroup client, HTML authoring program and IRC chat client. The Composer is simple but it handles tables, CSS, positioned layers and more without sweat. Add-ons currently include Scribefire, the blog editor that integrates with your browser and lets you easily post to your blog.
NVU: (pronounced N-view, for a “new view”) is a complete Web Authoring System for Linux Desktop users as well as Microsoft Windows users to rival programs like FrontPage and Dreamweaver. Use NVU to create Web pages and manage a Website with no technical expertise or knowledge of HTML.
OpenLaszlo: provides developers with a platform to create zero-install Web applications with user interface capabilities of desktop client software. In other words, OpenLaszlo applications developed on one machine will run on all leading Web browsers on all leading desktop OS. These applications, like Flash, provide animation, layout, data binding, server communication and more.
Bluefish: Try Bluefish as one option that can save you money and, possibly, time.
ConTEXT: This application is a small, fast and powerful freeware programmers text editor, developed to serve as a secondary tool for software developers.
XML Copy Editor: is a versatile XML editor primarily focused on text editing with XML files. However, XML Copy Editor provides many other features including validation of DTD and XML schemas – as well as XSLT and XPath with tag-free editing. Both tools are Windows applications.
This information was borrowed from http://whdb.com
