{Creating commented editions with \TeX} {Boris Veytsman}%School of Systems Biology, GMU {There are many ways to create critical editions, more general ``commented'' editions, with layers of commentary accompanying the main text. Packages like \code{bigfoot}, \code{manyfoot}, \code{*edmac} and others help to typeset different variants of them. Recently Instituto Nacional de Matem\'atica Pura e Aplicada, Brazil (\acro{IMPA}) requested yet another version for its series of mathematics textbooks for Brazilian schools. This series is designed as combinations of students' textbooks and the teacher's book. The teacher's book reproduces pages from the students' book, and adds a layer of comments around them. The package \code{commedit}, commissioned by \acro{IMPA}, hacks the output routine for the production of students' and teachers' version from a single source.}