Hello, I am using cygwin on a Windows XP system. I can build boost 1_32.0 with no problems. If i Try to build boos_1.33 The build failed with the following error: ./bjam -sTools="gcc" --prefix=/usr stage Building Boost.Regex with the optional Unicode/ICU support disabled. Please refer to the Boost.Regex documentation for more information (and if you don't know what ICU is then you probably don't need it). unknown target type for <@boost!libs!test!build>libboost_prg_exec_monitor.dll The error doesn't depend on prefix. what is wrong ??? buy Bernd