Daniel is a mathematician by training, but today his interests lie in open standards, and primarily the OpenDocument format.

Daniel has been involved in the OpenOffice.org project, one of the first office suites to fully support the OpenDocument format. Today he focuses his efforts on promotion of OpenDocument.

Daniel is one of the founding members of the OpenDocument Fellowship and continues to be a major contributor to the Fellowship. Some of his work includes:

• Writing articles and white papers, for example:
  The white paper titled Using open standards to promote competition and close the Digital Divide
  Format overview, an introduction to the OpenDocument format internals
  The Future Is Open: What OpenDocument Is And Why You Should Care (30 Jan 2005), a summary of the history of OpenDocument up to early 2005
• Member of the Project Committee, which oversees development projects funded by grants.
• Development work; for example, he is one of the developers of these projects:
  ODF Viewer
  ODF Tools