Hi there, when I built the 1_30_2 Python Library, I got: libboost_python.so now, with 1_31_0, I get several libs but that one: libboost_python-gcc-1_31.a libboost_python-gcc-1_31.so libboost_python-gcc-1_31.so.1.31.0 libboost_python-gcc.a libboost_python-gcc-d-1_31.a libboost_python-gcc-d-1_31.so libboost_python-gcc-d-1_31.so.1.31.0 libboost_python-gcc-d.a libboost_python-gcc-d.so libboost_python-gcc-mt-1_31.a libboost_python-gcc-mt-1_31.so libboost_python-gcc-mt-1_31.so.1.31.0 libboost_python-gcc-mt.a libboost_python-gcc-mt-d-1_31.a libboost_python-gcc-mt-d-1_31.so libboost_python-gcc-mt-d-1_31.so.1.31.0 libboost_python-gcc-mt-d.a libboost_python-gcc-mt-d.so libboost_python-gcc-mt.so libboost_python-gcc.so Unless I made a mistake in the building step which prevented libboost_python.so to be created, the first solution that comes to my mind to solve this backward compatibility problem would be to create a symlink from libboost_python.so to one of the new libraries. The question is, what would you recommend: libboost_python-gcc.so or libboost_python-gcc-mt.so (or none of the above, but....) thanks a million marco