Command Prompt, Inc. have released DocParse, commercial software that converts valid HTML into DocBook SGML.

Announcing the tool, Joshua Drake writes:

DocParse will correctly convert multiple documents, lists, and tables. After the conversion process is finished, the user will only need to perform basic formatting to insure the document appears as they wish.

DocParse is currently available for Linux x86 only, with releases for PowerPC (YellowDog Linux) and MacOS X imminent. Licensing is available on a per-seat or subscription basis.