The thread lib isn't currently building with msvc-8, cygwin and Mingw32: MSVC Errors: msvc.link.dll ..\..\..\bin.v2\libs\thread\build\msvc-8.0\debug\threading-multi\boost_thread-vc80-mt-gd-1_35.dll ..\..\..\bin.v2\libs\thread\build\msvc-8.0\debug \threading-multi\boost_thread-vc80-mt-gd-1_35.lib Creating library ..\..\..\bin.v2\libs\thread\build\msvc-8.0\debug\threading-multi\boost_thread-vc80-mt-gd-1_35.lib and object ..\..\..\bin.v2\libs\thread\build\msvc-8.0\debug\threading-multi\boost_thread-vc80-mt-gd-1_35.exp thread.obj : error LNK2019: unresolved external symbol "private: __thiscall boost::thread::thread(class boost::thread &)" (??0thread@boost@@AAE@AAV01@@Z) referenced in function "public: static class boost::thread __cdecl boost::thread::self(void)" (?self@thread@boost@@SA?AV12@XZ) ..\..\..\bin.v2\libs\thread\build\msvc-8.0\debug\threading-multi\boost_thread-vc80-mt-gd-1_35.dll : fatal error LNK1120: 1 unresolved externals call "c:\Program Files\Microsoft Visual Studio 8\VC\vcvarsall.bat" x86 > nul link /NOLOGO /INCREMENTAL:NO /DLL /DEBUG /subsystem:console /out:"..\..\..\bin.v2\libs\thread\build\msvc-8.0\debug\threading-multi\boost_thread-vc80-mt-gd-1_35.dll" /IMPLIB:"..\..\..\bin.v2\libs\thread\build\msvc-8.0\debug\threading-multi\boost_thread-vc80-mt-gd-1_35.lib" @"..\..\..\bin.v2\libs\thread\build\msvc-8.0 \debug\threading-multi\boost_thread-vc80-mt-gd-1_35.dll.rsp" if %ERRORLEVEL% NEQ 0 EXIT %ERRORLEVEL% if exist "..\..\..\bin.v2\libs\thread\build\msvc-8.0\debug\threading-multi\boost_thread-vc80-mt-gd-1_35.dll.manifest" ( mt -nologo -manifest "..\..\..\bin.v2\libs\thread\build\msvc-8.0\debug\threading-multi\boost_thread-vc80-mt-gd-1_35.dll.manifest" "-outputresource:..\..\..\bin.v2\libs\thread\build\msvc-8.0\debug\threading-multi\boost_thread-vc8 0-mt-gd-1_35.dll;2" ) Cygwin has lots of compiler errors: looks like it should be configured to use the POSIX thread lib rather than the Win32 API's? Mingw32 has the following build errors: gcc.compile.c++ ..\..\..\bin.v2\libs\thread\build\gcc-mingw-mw\debug\threading-multi\thread.o ..\..\..\libs\thread\src\win32\thread.cpp: In static member function `static boost::thread boost::thread::self()': ..\..\..\libs\thread\src\win32\thread.cpp:160: error: no matching function for call to `boost::thread::thread(boost::thread)' ../../../boost/thread/win32/thread.hpp:69: note: candidates are: boost::thread::thread(boost::thread&) Really we shouldn't be getting this many breakages this close to a release! :-( John Maddock.