Hi, Well, heads up. I'm doing lots of refactorizations. It all started with the include dependency bug noted by John Maddock. There's a nasty cyclic dependency happening somewhere that I tried to track. Along the way, I caught unwanted dependencies that stem from violations of the modular design of fusion that allows (by protocol) only acyclic module relationships. A bit of refactorizations after, the new layer/module hierarchy is (hight to low): mpl algorithm | functional container | view | adapted | tuple sequence iterator support This might still change a bit after odds and ends fall into place. If you want something stable, now, there's this new "include" directory that is a flat, MPL like, repository of include files that forward to the proper files (e.g. boost/fusion/include/vector.hpp will always point to where fusion::vector is). I highly recommend users to use it and for developers (Dan and Tobias etc.) to put all relevant forward headers there. Regards, -- Joel de Guzman http://www.boost-consulting.com http://spirit.sf.net