LinuxDoc is an SGML DTD which is similar to DocBook. Matt Welsh created it, and version 1.1 was announced ^[1] in 1994. It is primarily used by the Linux Documentation Project. The DocBook SGML tags are often longer than the equivalent LinuxDoc tags.^[2]

LinuxDoc has a more succinct DTD than DocBook. Users of small to medium-size projects have found that it suits their purposes better than DocBook.^[3]

The Debian distribution of Linux has a Linuxdoc-tools package.