Though the debate over the superiority of .Net versus that of Java 2 Platform, Enterprise Edition (J2EE) seems a hot topic in today’s technology circles, many people believe it is simply a marketing battle of little consequence. Marketing battle or not, the debate’s effects will one day prove critical in software evolution. Thus, Sun Microsystems’ and Microsoft’s executive teams have committed significant marketing budgets in an effort to gain advantage. Should Microsoft lose this battle, the operating system might simply become a lifestyle choice. Sun’s victory could one day enable software to run on any operating system, causing Microsoft’s dominance in operating systems to slowly fade as other operating systems, capable of running the same software, come to market. On the other hand, should Microsoft succeed, it will further entrench its technology suite as the de facto standard for the foreseeable future. In this article, we compare the J2EE and .Net technologies to help you decide which one is worth the investment.