Hylt is a file format that provides HYperLinked Text with minimal markup, meant to be both easy to view in any program and easy to keep in a version control system. The Hylt project covers the file specification, viewers, and tools to manage Hylt files.
Use Xilize to create XHTML pages or entire websites with just a plain-text editor. The markup is similar to Textile and extensible via BeanShell. Run as a jEdit plugin, from the command line, or embed in a Java program. Small, fast, easy-to-use.
A webbased XML development toolkit to edit, validate and preview XML files. This program gives you a structured view of the XML data.
It has support for multiple XML formats: SVG, DocBook, XHTML and more. phpXIedit is written in PHP.