Ric, I came across this while searching for some stuff about the preprocessor: _MSC_VER: Defines the compiler version. Defined as 1200 for Microsoft Visual C++ 6.0. Always defined. (from MSDN October 2001) However, in ANTLR it is used MSVC_VER ??? Jorge Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/