Instant Preview and the TEX daemon

Instant Preview is a new package, for use with Emacs and xdvi, that allows the user to preview instantly the file being edited. At normal typing speed, and on a 225MHz machine, it refreshes the preview screen with every keystroke. Instant Preview uses a new program, dvichop, that allows TEX to process small files over 20 times quicker than usual. It avoids the overhead of starting TEX. This combination of TEX and dvichop is the TEX daemon. One instance of the TEX daemon can serve many programs. It can make TEX available as a callable function. It can be used as the formatting engine of a WYSIWYG editor. This paper will demonstrate Instant Preview, describe its implementation, discuss its use with LATEX, sketch the architecture of a WYSIWYG TEX, and call for volunteers to take the project forward. Instant Preview at present is known to run only under GNU/Linux, and is released under the GPL. It is available at: http://www.activetex.org.