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 is built on 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 © 2005-2008 R. D. Tennent.