I have a library that uses boost and also uses a pre-release version of the ptr_container (header only) library that eventually made it into boost 1.33 (I think). I would like people to be able to compile my code with various versions of boost. I've had it working with 1.31 and 1.32, and expect to have it working with 1.33 when that reaches my distribution. I have a subdirectory with the pre-release ptr_container library and some supporting code from elsewhere in boost. This is in a "boost" subdirectory of my project, which has included the directory above that unconditionally in my compilations. With 1.33 I think I want to ignore my local stuff completely. I'm using autoconf and libtool. Are there autoconf macros available for detecting the boost libraries? Do people have any suggestions about the best way to proceed? One possibility that occurs to me is to test for the version of the library at configure time, and make the include path depend on the results. Thanks. Ross Boylan