C++: GCC prior to 4.7 does not support the override keyword. So if using earlier versions of GCC, just remove override. This allows compilation on ancient GCC and GCC based Xcode. Also remove virtual from the application, I don't think it is needed and old GCC pukes on it when it is there.

prefix=@prefix@
exec_prefix=${prefix}
libdir=${exec_prefix}/lib
includedir=${exec_prefix}/include
 
Name: dwindows
Description: Dynamic Windows Cross platform UI Toolkit
Version: @VERSION@
Libs: -L${prefix}/lib -ldwindows @LIBS@
Cflags: -I${prefix}/include @CFLAGS@ -D@DW_DEFINE@