I'm building using: bjam -d+2 -j8 cxxflags='-march=native -Wno-unused-local-typedefs' -sHAVE_ICU=1 - sEXPAT_INCLUDE=/usr -sEXPAT_LIBPATH=/usr/lib64 --layout=tagged threading=single,multi link=shared stage In user-config.jam I added: using python : 3.3 : /usr/bin/python3 : /usr/include/python3.3m ; I wind up with stage/lib/libboost_python.so stage/lib/libboost_python3.so But AFAICT, they were build the same way. It's be nice if one was built against python2 and the other python3, but that doesn't appear to be true. AFAICT, both were built from the same sources (using /usr/include/python3.3m). What I'd like is to build both python2 and python3 from the same source tree, installing the final shared libs into the same destination dir. Right now I have 2 different source trees, and build switching the one line in user- config.jam.