Macro Package Intro (The GNU Troff Manual)

### 1.4 Macro Packages

Elemental typesetting functions can be be challenging to use directly with complex documents. A macro facility specifies how certain routine operations, such as starting paragraphs, or printing headers and footers, should be performed in terms of those low-level instructions. Macros can be specific to one document or collected together into a macro package for use by many. Several macro packages available; the most widely used are provided with `groff`. They are `man`, `mdoc`, `me`, `mm`, `mom`, and `ms`.