lop a program and then share it with others on the Web. However, lacking both debugger and profiler, <span style="color:darkblue">Pengines Scratchpad</span> is far from a full-fledged IDE for Prolog embedded in HTML, and to avoid compromising the server it does not allow you to execute "dangerous" Prolog predicates such as predicates reading and writing files. (It does however allow you to use <code>pengine_input/1</code> and <code>pengine_output/1</code> but they will only "read" from and "write" to your w