Method and system for SGML-to-HTML migration to XML-based system

A technique, system, and computer program by which content created from source files in a first data format and converted to presentation files in a second data format can be read and used by a subsystem which reads content in a third data format other than the first and second data formats. Identifying information from the source files and/or presentation files is extracted and stored in a map file in the third format. If desired, a Table of Contents (TOC) file in the third data format can also be created by using the map file and a TOC file in the second data format. The first data format can be Standardized General Markup Language (SGML), the second data format can be HyperText Markup Language (HTML) and the third data format can be Extensible Markup Language (XML).