Strategic and industrial analysis reveals it is extremely difficult to enter a market dominated by an existing platform. In fact, direct or indirect network effects give the established company's platform a considerable competitive edge. This is true of the numerical computation market and the Matlab + Simulink platform by MathWorks. The case study of Scilab Enterprises helps identify conditions of viability for breaking into such a market. We find that alone, the platform strategy is doomed to fail, but accompanied by an open strategy, entering a platform market becomes possible. We hypothesize that a platform strategy is successful when associated with an open innovation process (integration of the open source community) and supported by a business ecosystem (a huge community of developers, users, and allies). Copyright © 2015 ASAC. Published by John Wiley & Sons, Ltd.