SciTE is a SCIntilla based Text Editor. Originally built to demonstrate Scintilla, it has grown to be a generally useful editor with facilities for building and running programs.
XMLmind XML Editor is a strictly validating, near WYSIWYG, DocBook editor, DITA editor, MathML editor, XHTML editor, XML editor. Because XMLmind XML Editor is highly extensible, it may be also be used to create documents conforming to your own custom schema.
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.
WinEdt is a powerful and versatile all-purpose text editor for Windows with a strong predisposition towards the creation and compilation of LaTeX documents...
Notepad++ is a free (as in "free speech" and also as in "free beer") source code editor and Notepad replacement that supports several languages. Running in the MS Windows environment, its use is governed by GPL License.
XEmacs is a highly customizable open source text editor and application development system. It is licensed under the GNU Public License and related to other versions of Emacs, in particular, GNU Emacs.
XVI32 is a freeware hex editor running under Windows 9x/NT/2000/XP/Vista/7. The name XVI32 is derived from XVI, the roman notation for the number 16. XVI32 and all of its components are developed by myself.