I've finally gotten serialization for XML archives to compile using Boost 1.33.1. Now I'm trying to execute the test. Unfortunately, the first archive output statement outArchive << BOOST_SERIALIZATION_NVP(testObj_out); triggers an exception saying, "unrecognized XML syntax". The output file looks like <?xml version="1.0" encoding="UTF-8" standalone="yes" ?> <!DOCTYPE boost_serialization> <boost_serialization signature="serialization::archive" version="3"> <testObj_out class_id="0" tracking_level="0" version="1"> <px class_id="1" tracking_level="1" version="0" object_id="_0"</boost_serialization> Note that the closing ">" for the px element is missing, which is probably the reason why there is no newline before </boost_serialization>. The serialize() function for the class object being archived has one ar & for a base class plus three data members. So, it looks like serialization is going awry while string to write the initial class element and never gets to the class contents. By the way, I've never seen the XML root element (<boost_serialization>) with attributes. Is that standard? Any ideas? Merrill