Geany is a text editor using the GTK2 toolkit with basic features of an integrated development environment.
Aptana Studio - Build web applications quickly and easily using the industry's leading web application IDE.
NetBeans IDE - Editor Support for HTML, JavaScript, and CSS. The NetBeans JavaScript and CSS editors are the perfect choice for Ajax development.
Eclipse - Eclipse is an open source community, whose projects are focused on building an open development platform comprised of extensible frameworks, tools and runtimes for building.
Eclipse is a multi-language software development environment comprising an integrated development environment (IDE) and an extensible plug-in system. 
Bluefish is a powerful editor targeted towards programmers and webdesigners, with many options to write websites, scripts and programming code. Bluefish supports many programming and markup languages, and it focuses on editing dynamic and interactive websites.
