Xedit is the visual text editor that comes with the X Window System distribution. It's a standard visual text editor like notepad that does nothing very interesting, and does it well.
Xedit would typically be invoked with "xedit &" on the command line. You can put it in your .xsession file, but I'm not sure why you would.
The xedit window is divided horizontally into a few different parts. At the top are quit, save, and load, and a text box for entering the name of the file you want to save or load. Below that is an text box that gives you general messages and also acts as a buffer for copying and pasting operations. Below that is a bar with some useful information (line number, mostly), and below that is the text box for the file. The visual design is compact and works well down to a little more than 200x200 pixels, where it becomes crowded.
The interface is a mishmash of different schools of text editing. It is vaguely moded, but it's not terribly useful, as it only has a handful of line-editing commands. In normal mode, there are a stack of familiar-looking ctrl and meta commands for navigating words, letters and lines, and so forth. Most people who used it (assuming they exist) probably just used the mouse with the buttons along the top.
Xedit is obviously not intended as competition for the more popular editors, but it is a good staple editor for the X environment, and rounds out the set of useful client programs included in the X11R6 distribution.
Xedit is written in C using Xlib, Xt, and the Motif widgets.