Prerex is an editor for creating esthetically pleasing course prerequisite charts using the TikZ LaTeX package.

The editor supports add, remove, cut-and-paste, and edit operations on diagram elements, and shifts of a list of specified elements or the entire diagram. The edited diagram may be saved, re-processed, and viewed in a PDF viewer, without exiting the editor.

Course prerequisite charts allow students to easily determine which prerequisites, corequisites and recommended prerequisites they need for a given course and their time slots. Course prerequisite charts also highlight the courses required by a degree.

prerex is used by departments in several universities, including Queen's University and Suffolk University.