The preprocessor documentation has a link to the Boostpro site which had an html version of the Appendix A of "C++ Template Metaprogramming" by Abrahams and Gurtovoy. Appendix A is "An Introduction to Preprocessor Metaprogramming", which is all about Boost PP. Alas Boostpro is no more and the link in the preprocessor documentation goes nowhere. I can remove the link and any notice of the introduction. But If either David Abrahams or Aleksey Gurtovoy are still around it would be nice to get the html pages which existed before and incorporate them into the Boost PP docs. Does anyone know how to contact either of them ? I can try their addresses in maintainers.txt but I do not want to directly encroach on their privacy if there is a better way.