I already tried the users list for Boost so I am cross-posting this. When I perform an "out-of-the-box" build on my Macbook Pro (Intel dual core) on Leopard (10.5) i get a motley collection of ppc and intel binaries that are useless on my Intel-based system unless I want to use the dynamic libraries only. None of the libraries are universal binaries and only the dynamic libraries are for the i386 architecture (see lipo output below). $lipo -detailed_info libboost_regex* input file libboost_regex-1_34_1.a is not a fat file input file libboost_regex-1_34_1.dylib is not a fat file input file libboost_regex-d-1_34_1.a is not a fat file input file libboost_regex-d-1_34_1.dylib is not a fat file input file libboost_regex-d.a is not a fat file input file libboost_regex-mt-1_34_1.a is not a fat file input file libboost_regex-mt-1_34_1.dylib is not a fat file input file libboost_regex-mt-d-1_34_1.a is not a fat file input file libboost_regex-mt-d-1_34_1.dylib is not a fat file input file libboost_regex-mt-d.a is not a fat file input file libboost_regex-mt.a is not a fat file input file libboost_regex.a is not a fat file Non-fat file: libboost_regex-1_34_1.a is architecture: ppc7400 Non-fat file: libboost_regex-1_34_1.dylib is architecture: i386 Non-fat file: libboost_regex-d-1_34_1.a is architecture: ppc7400 Non-fat file: libboost_regex-d-1_34_1.dylib is architecture: i386 Non-fat file: libboost_regex-d.a is architecture: ppc7400 Non-fat file: libboost_regex-mt-1_34_1.a is architecture: ppc7400 Non-fat file: libboost_regex-mt-1_34_1.dylib is architecture: i386 Non-fat file: libboost_regex-mt-d-1_34_1.a is architecture: ppc7400 Non-fat file: libboost_regex-mt-d-1_34_1.dylib is architecture: i386 Non-fat file: libboost_regex-mt-d.a is architecture: ppc7400 Non-fat file: libboost_regex-mt.a is architecture: ppc7400 Non-fat file: libboost_regex.a is architecture: ppc7400 I made the assumption that Boost would, as a default, build for the native architecture it was building one since most of the other libraries I use have been doing that for nearly 2 years. My mistake. To have it build ppc on an intel platform--that was completely unexpected at this late date. The jam user configuration is very simple gives not hint of why bjam builds static ppc and dynamic intel binaries. ugh. What a mystery to someone who knows little about bjam. Searching the Boost site for the key word "universal binaries" found nothing. Searching for "universal OS X" gave four generic uses of the word "universal" but nothing of help. Anybody have any experience building Boost as a universal library set? If not... It's been over a year since I had to hack a build so I need to refresh my memory. It my well be time to pour another cup of java, take the red pill, and see how deep the rabbiit hole goes.