Delphi defines the following standard conditional symbols. VER80 - Delphi .x VER90 - Delphi 2.x VER93 - CBuilder .0 VER 00 - Delphi 3.x For example the following would compile in the correct uses statement in Delphi 2 and Delphi 3 respectively. {$IFDEF VER90} uses system, windows, oleaut; {$ENDIF} {$IFDEF VER 00} uses system, windows, comobj; {$ENDIF} The version numbers for Delphi , 2 and 3 correspond to version 8.0, 9.0 and 0.0 of the Object Pascal compiler. For additional information on conditional compiles and compiler directives see appendix B in the Delphi 3 users guide.