Because the event will be pen and paper, only printouts (or screenshots) of DS9 will be used. As a result, teams do not have to have DS9 on their computers to compete. Instead, if you cannot download DS9 simply use JS9 (the online tool) to practice for the competition. What is tested instead is students familiarity with the programs output and how to analyze/interpret that output. So however you get it to run on your personal, school, or library computers (and whichever version you use) is really a fine way to gain that understanding.