The X2 Editor was derived from Tim Baldwin's XE sample editor. Extensive modifications have been made to the functionality and internal workings of the editor, but the author is indebted to Tim for sharing the original source code.
In functionality X2 derives from the E family of editors, E3 and EOS2 in particular. The authors of these editors include Clark Maurer, Bryan Lewis, Jean Christophe Bandini, Richard Redpath, Davis Foulger, and Larry Margolis. E in turn was influenced by Personal Editor, by Jim Wyllie.
X2 also includes some features from VM's XEDIT editor. XEDIT was originally written by Xavier de Lamberterie.
The Unix versions make use of X-Windows routines, most of which are taken from Scott Schaffer's VE editor.
There have been dozens of people who have contributed ideas, macros, encouragement, and of course bug reports. I can't name you all, but I am very grateful for the interest you have shown in this project. Cindy Ross endured years of bugs, crashes, and lost data during the initial development of the XWing version of the editor, and I am very grateful for her testing efforts and for her encouragement and enthusiasm for this very long project.
The author may be contacted through the Internet at firstname.lastname@example.org.