All - Since I'm the review manager I'm not doing a formal review of the library, but I thought I'd share some code and a few thoughts. If serialization is accepted users people will ask me and other library authors to provide serialization support for some of the types in their libraries. So to get a feel for the difficulty of extending serialization for new types I wrote the serialization code for gregorian::date and some example code to try it out. Of course this sort of extension is a critical aspect of the library design since everyone with a unique type will need to write serialization code. Overall I felt the docs did a pretty good job of explaining what need to be done and the code turns out to be reasonably trivial. Note that the code is more verbose than required as I did not use all of Robert's macros. Also, gregorian::date doesn't currently have a default constructor and hence it is a more challenging case (as I recall the first submission of the serialization lib required default constructors). When programming with dates and times putting them into collections is quite common. Fortunately, one of the most impressive aspects of the current serialization library is the ability to handle stl collections. So I was glad to find (as I expected) that by enabling the serialization of gregorian::date serialization of collections of date's comes along for free. I've attached the code and the serialized file for your reading enjoyment :-) Jeff