2.2. Ok, but what is DocBook really?

More broadly defined, DocBook is the DTD mention above and the mechanisms to transform DocBook documents to a useful format.

There are at least three separate existing mechanisms that I know of for transforming DocBook instances, each based on a different stylesheet language. If none of these mechanisms suit your needs, it is possible to create a new one from scratch, though that would be non-trivial. The important point is that DocBook is an open standard, so ultimately you own your data.

Of the existing mechanisms, two are free (as in freedom and beer) open source and a third is commercial: