Xflag is an X client using Motif (libXm) widget library. If you have xmkmf on your machine, just say xmkmf than compile xflag with the generated makefile by saying make and that's it. Or, you can say something like the following line (this example compiles xflag on Sun's Solaris2.X): cc -o xflag -I$MOTIFHOME/include xflag.c \ -L$MOTIFHOME/lib -lXm -lXt -lX11 -lm -lsocket \ -L/usr/ccs/lib -lgen -lnsl where $MOTIFHOME points to the path of MOTIF directory at your machine.