This package consists of prerex.sty, a LaTeX package for producing charts of course nodes linked by arrows representing pre- and co-requisites, and prerex, an interactive program for creating and editing chart descriptions. The implementation of prerex.sty uses PGF, so that it may be used equally happily with latex or pdflatex; prerex itself is written in C.

The package includes source code for a previewer application, a lightweight Qt-4 and poppler-based prerex-enabled PDF viewer.

The author is Bob Tennent. The package is Copyright © 2006-2014 R. D. Tennent.