HelpMaker is a Help Authoring Tool to make WinHelp, HTML-Help, HTML-Website and RTF (i.e., manuals) files. HelpMaker is fully functional GUI help authoring tool written in Delphi. Many open-source developers use this to document their open-source project
Research Description Language (RDL) is an XML application for describing and publishing scientific research efforts. Research Editor (REd) is a tool for editing RDL documents, and exporting them to LaTeX, PDF, etc.
TeXPerfect plans to be a cross-platform, extensible, user-friendly yet expert-tunable visual TeX implementation. The most important feature will be a split screen (inspired by WordPerfect(R) Reveal Codes) showing the underlying TeX code.