di­ag­mac – A di­a­gram draw­ing pack­age

The pack­age comes in two parts: first, some macros that are gen­er­ally ap­pli­ca­ble to draw­ing di­a­grams in LaTeX; and sec­ond, macros spe­cific to draw­ing cat­e­gory the­ory di­a­grams.
The pack­age was writ­ten for LaTeX 2.09, but con­tin­ues to work un­der LaTeX 2e; how­ever, an up­dated ver­sion, that uses pic­t2e, is also avail­able.