I talked to an organization a few days ago that wasn't using Boost.Thread because of the catch(...) clause in the thread launching functions. They wanted the usual Win32 termination behavior (where you get a stack backtrace) instead. While that might seem like a silly reason not to use Boost.Thread, it's legitimate. I told them about several ways to work around that issue, but I think all of them are more hassle and provide a less useful result (to them) than simply letting the exception leak. I wonder if the that would be a conforming implementation, whether a call to terminate() is required, and whether a preprocessor switch to allow exceptions to leak would be a good idea? -- Dave Abrahams BoostPro Computing http://www.boostpro.com