Colleagues, I posted this before, but didn't get answers to some questions so far. I think I possibly addressed the "output" part of requirement 7(a) from the IOStreams Roadmap https://svn.boost.org/trac/boost/wiki/IostreamsRoadmap in this library https://code.google.com/p/async-ostream/ Does it make sense if I create a patch for Boost.IOStreams to add those five files and ask the maintainer (or volunteers) for feedback? Regards, Gene