Hi, The latest version of pqs , pqs_3_0_7 is now in the vault. For this version I spent some time in cleaning up, reorganising and extending the documentation. I have added some information on creating ones own quantities but its not complete yet. The tests have been reorganised so that emphasis is now on testing the interface and tests are more systematic and comprehensive too. I have also added an implementation of angles(radians, steradians, degrees, minutes,seconds etc) and added two sub namespaces of pqs; two_d and three_d, where can be found various geometry entities, such as vectors and matrices, that can be used directly with quantities. Unfortunately I havent had time to document these or write significant tests yet. Some clues as to proposed useage style for angles (which is based on the same style as for quantities) can be seen in <libs/pqs/test/angle/ange_test1.cpp> BTW. For anyone interested in the VC8_0 ADL bug, the vector class in <boost/pqs/three_d/vect.hpp> exhibits the behaviour too, but only when the value_type is a quantity (or any UDT???) IIRC. Because its a simpler class than the physical quantity that earlier showed the bug it might be easier to isolate it which I will try to do at some stage. regards Andy Little