When building Boost_1_33_1 on MacOSX 10.4 with Darwin tools (gcc 4.0.1), if I try to build with dynamic linking enabled (i.e. "<runtime-link>dynamic" in the bjam command), there are link-time failures for the three libraries that are part of Boost.Test. I think this is likely the same as a known problem with NT mentioned in recent email from Gennadiy: the prg_exec_monitor and test_exec_monitor libraries fail because __Z9test_mainiPPc is undefined, while the unit_test_framework library fails due to __Z20init_unit_test_suiteiPPc being undefined. It looks like the Jamfile for Boost.Test has a workaround for NT here, which presumably needs to be extended to MacOSX as well. There is a block of code in libs/test/build/Jamfile that looks like this: local TEST_DLLs ; if ! $(NT) && ( ! $(UNIX) || $(OS) != CYGWIN ) { TEST_DLLs = TRUE ; } It looks like the conditional there needs to also be false for MacOSX. After grovelling around in the jam configuration, it looked like the necessary change was to replace $(OS) != CYGWIN with ( $(OS) != CYGWIN && $(OS) != MACOSX ) i.e. the test should be if ! $(NT) && ( ! $(UNIX) || ( $(OS) != CYGWIN && $(OS) != MACOSX )) Unfortunately, that change doesn't seem to be sufficient to disable the attempt to build dll's for Boost.Test. I have no idea why, and no idea how to figure that out, being largely unfamiliar with jam and Jamfiles. Alternatively, is there a way from the bjam command to indicate that I want <runtime-link>dynamic except for some specific set of libraries? (I know how to exclude libraries completely, which would probably solve my problem for prg_exec_monitor and test_exec_monitor, since we aren't using them, but doesn't deal with the unit_test_framework library, which I do need.) It would seem from Gennadiy's recent burst of messages that this may no longer a problem or about to no longer be a problem on CVS HEAD, but we're not prepared to go there and would prefer a patch to the 1.33.1 release. Sorry I didn't notice this when checking out the release candidate, but this platform has only just been bumped up in my priorities enough for me to start trying it.