Hello, I guess I'm not quite ready to request a formal review for the Exception lib I wrote, but because of the initial interest in it I do want to propose adding it to Boost. So I wrote documentation, and adapted the source code to Boost. Please check it out: http://www.revergestudios.com/exception/exception.htm If you click Download on that page, you can get a .zip file with the source code, tests, and an example, complete with Boost Build Jamfiles. All of the Exception lib code is contained in boost/exception.hpp. The code has been tested with msvc 7.1, 8.0 and gcc 3.4.4. Peter Dimov mentioned the system_error proposal from Beman Dawes. I will read it carefuly and will think how it can be integrated with the Exception lib. Thanks, Emil