I've installed STLPort 5.0 in order to track down some test case errors. Right away I have a problem. It seems that by default STLPort 5.0 with VC 7.1 uses an unsigned short for wchar_t (I could be wrong, the information is kind of thin). I've looked at the config stuff and its not clear that config and STLPort address this issue. That is, its not clear whether the Boost Macro for this feature is guarenteed to be in sync with the way that STLPort 5.0 is built. The tests don't make it clear how the STLPort is built in this regard. Ideally, the config system would be able to set the appropriate BOOST macros in accordance with the particular build of STLPort library. I'm not sure whether or not such a thing is possible. I would be interested in hearing any information on this. Robert Ramey