Hi, I've just uploaded an upgrade of Boost.MultiIndex that provides serialization support at: http://groups.yahoo.com/group/boost/files/multi_index_120104.zip Docs are not yet fully upgraded, but there's some material on serialization support on the advanced topics page, plus a test case. I'd be grateful if those interested in Boost.MultiIndex can give this a try, and report about problems, missing features, improvements, etc. The implementation is a little complex, so some source code reviewing would be appreciated. If no major objections are risen, I'll commit this to the CVS in a few days. Oh, and kudos to Robert for bringing in such a powerful library as Boost.Serialization! Thank you, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo