Substance is a fully web-based document authoring and publishing platform. With Substance, writers, journalists, scientists and everyone else who's interested in publishing can use an open platform for writing and sharing articles.
The Aptana IDE is a free, open-source, cross-platform, JavaScript-focused development environment for building Ajax applications. It features code assist on JavaScript, HTML, and CSS languages, FTP/SFTP support and a JavaScript debugger to troubleshoot your code.