Thanks for the kind words about s7! Are you running Linux? If so, this works for me: /home/bil/pure-snd/ g++ -c s7.c -I. -g /home/bil/pure-snd/ g++ exx.c -o exx s7.o -I. -lm -ldl /home/bil/pure-snd/ exx > (plus 2 3) 7 > (plus :blue 2) 66 > (exit) where "exx.c" has the example code from s7.html.