daps
An open source program for transforming DocBook XML into output formats such as HTML or PDF. tldr-pages
On several platforms
Several platforms
Check if a DocBook XML file is valid
daps --docconfig path/to/file.xml validateIdentifyConvert a DocBook XML file into PDF
daps --docconfig path/to/file.xml pdfIdentifyConvert a DocBook XML file into a single HTML file
daps --docconfig path/to/file.xml html --singleIdentifyDisplay help
daps --helpIdentifyDisplay version
daps --versionIdentify