DocBook is an open standard XML content model for writing documentation. In its original development it was intended specifically for technical documentation for hardware and software, but its rich semantic model today makes it suitable for any type of documentation.

DocBook is equally well-suited for both topic-based authoring and for longer documents. What mainly defines DocBook compared to other XML-based content models such as DITA or S1000D is that it is more flexible in terms of the structure of elements. While it does govern the structure of documents to enforce consistent content, it takes a middle-ground and is more pragmatic and less rigid. Topic typing can be enforced, but is an option in DocBook rather than built into the model as in DITA.

The XML content model used in the Paligo CCMS is based on DocBook.

The DocBook open standard is developed and maintained by the OASIS DocBook Technical Committee.