CFWheels is an open source CFML (ColdFusion Markup Language) framework inspired by Ruby on Rails that provides fast application development, a great organization system for your code, and is just plain fun to use.
CMSimple is a CMS (content management system) designed primarily for the creation and maintenance of small sites, easy for commercial, personal or association websites. It is small, simple, smart and easy!
DAV Explorer is a Java application which uses Java 2 (tested with JDKs 1.2 to 1.4). and has successfully been run on Microsoft Windows from Windows 95 to Server 2003, Solaris and Linux.
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.
Apache Lenya is an Open Source Java/XML Content Management System and comes with revision control, multi-site management, scheduling, search, WYSIWYG editors, and workflow.