I haven't seen any posts about this, so please pardon me if I have missed it, but Boost does not currently build on Mac OS X Tiger with the 'darwin' toolset because the option -fcoalesce-templates has been removed from the Apple build of GCC 4.0. I have made simple modifications to my checked out copy of the latest Boost source to allow the libraries I need to build, but my changes would break the usability of Boost libraries on previous versions of OS X that need -fcoalesce-templates. I would be happy to submit a patch and run any tests if someone could suggest how I would go about modifying boost/tools/build/v1/darwin-tools.jam in a backwards compatible manner. Thanks. -Patrick -- Patrick L. Hartling | VP Engineering, Infiscape Corp. PGP: http://tinyurl.com/2oum9 | http://www.infiscape.com/