I just added an optimization to some code for systems with octet- sized bytes. I have such a system; so I tested that code. I added a further optimization for little-endian systems. Unfortunately, my computer is big-endian, so I have no way to test the second change. So if you have access to a computer with octet-sized bytes (CHAR_BIT == 8) and larger integers in little-endian format, can you help? The code is on our Subversion server, in the sandbox section, just checked in as revision 48224. Check-out or export the <http:// svn.boost.org/svn/boost/sandbox/md5> directory. The headers are in the "boost" subdirectory, of course. There is one mandatory source file at "libs/coding/src/md5.cpp". There are three test files at "libs/coding/test/md5*test.cpp". Compile all those together with our Unit Test and Serialization libraries. (On my system, I made a project file with a three sub-targets: Boost.Test unit-test, Boost.S11N, and md5.cpp; which the target with the test files compiled linked to.) The "md5.cpp" has the optimized code. The optimized code doesn't activate unless CHAR_BIT is 8 and the file's BOOST_CONTROL_OPTIMIZE_OCTET_BYTES macro is set (or overridden) to 1. The little-endian extra optimization is activated with the BOOST_LITTLE_ENDIAN macro and is mandatory (if valid). I added three now-commented-out #error lines to test which case was activated, which confirmed I'm using a not-little endian system. You can un- comment those to check for yourself. Let me know if the little endian code works, or tell me how to fix it (if not). If you want, you can comment-out the little endian code to test the endian- agnostic code, and then redefine or override BOOST_CONTROL_OPTIMIZE_OCTET_BYTES to be 0 to test the octet-agnostic code (which explodes the packed array into a bool array before combining). Thanks in advance.... -- Daryle Walker Mac, Internet, and Video Game Junkie darylew AT hotmail DOT com