Hello Hartmut! I looked through the wave Jamfile.v2 and was able (???) to fix compilation and linking errors of a newer wave release. First error was that I could not build wave only lib. This was caused by the line nr. 34 (RC3) there is written: /boost/filesystem//boost_filesystem The correct filesystem reference at least on my Windows XP VC80 Express Edition machine is: /boost//filesystem The next issue relates to the changes you did where linking errors happen. To fix this issue I added a dependency (don't know if this was a correct way to do...) to the thread library: /boost//thread At the line 35. This dependency is only needed if wave head is compiled. I still have a problem that during the initialization phase of wave/spirit's static variables my app crashes. May be you can currently switch off the multi-threaded support in the head revision (or make it available via a macro???), so that I can take files with the conditional processing feature only. Otherwise I am currently blocked because I can either select MT with conditional processing (=>app crashes) or ST without conditional processing. Would be great to get ST with conditional processing. The app crashes during the parsing of file: boost\wave\util\cpp_macromap_predef.hpp line 166. // __SPIRIT_PP_VERSION__/__WAVE_VERSION__ boost::wave::util::time_conversion_helper const compilation_time(__DATE__ " " __TIME__); May be there is an assertion, but Visual Studio unfortunately does not show this. With Kind Regards, Ovanes Markarian