DocBook documents, as they are (usually) technical documents, are meant for human consumption. Companies developed their own tools for formatting DocBook^[2], then as successive stylesheet standards became available, open source stylesheets for formatting or transforming DocBook were made available by Norman Tovey-Walsh. The original DSSSL stylesheets [DOCBOOKDSSSL] are no longer maintained; the XSLT 1.0 stylesheets are widely used and are actively maintained^[3] by Bob Stayton [DOCBOOK-XSL] and others; the XSLT 2.0 stylesheets were never as ubiquitous as the XSLT 1.0 stylesheets, and their development was discontinued in July 2020 in favour of the XSLT 3.0 stylesheets. The “xslTNG” XSLT 3.0 stylesheets do not yet have the same user base or the same number of contributors as the XSLT 1.0 stylesheets, but the XSLT 1.0 stylesheets had a 16-year head start.