twoside – Two-side typesetting in Plain TeX
Defines macros that produce output destined for two-sided printing, with a gutter margin as specified by the user. A running head may also be specified.
Maybe you are interested in the following packages as well.
- automagic: Automagic numbering in Plain TeX
- lettermac: Simple macros for writing letters (Plain TeX)
- twocolumns: Knuth's two-column output macros
- letter1: Letter formatting macros