Folks, I have just checked in a big refactoring of Jamroot. Over the time it has grown too big and too unstructured, so I've added a new module, boostcpp, and moved most of the scary logic there, also clarying that logical blocks. I have tested the changes the best I could, but it is possible something still breaks. So, if you observe some strange behaviour when building trunk, you might want to immediately report that to me. Thanks, Volodya