I installed ProDT 1.0.0 on Eclipse Indigo on Mac OS X 10.5.8 using update manager. At first the editor would give an error instead of opening existing .pl files. When I worked around that, I find that the configuration instructions aren't sufficient to let me run Prolog scripts, much less open an interactive Prolog session or use a single-step debugger. It looks from other comments that these tools do work for someone. But they aren't working for me.