Open Source for Mac OS X

KompoZer is a complete Web Authoring System that combines web file management and easy-to-use WYSIWYG web page editing capabilities found in Microsoft FrontPage, Adobe DreamWeaver and other high end programs.

KompoZer is designed to be extremely easy to use, making it ideal for non-technical computer users who want to create an attractive professional-looking web site without needing to know HTML or web coding. 

KompoZer is based on Gecko, the layout engine inside Mozilla; it's a super-fast, very reliable, standards conformant engine maintained on a daily basis by a wide community of developers. Its remarkable support of XML, CSS and JavaScript offers the best authoring platform on the market. Its architecture based on XUL makes it the most extensible editing tool ever.