Microsoft's web services architecture, pronounced dot-net. Despite the capital letters, it's not an acronym. .NET is the brand name for a set of proprietary Microsoft frameworks and technologies founded on XML web services standards. Standards compliance means that applications written using .NET should interoperate with those written in rival architectures, such as J2EE, the distributed application infrastructure based on Sun's Java language. However, interoperability is not portability; .NET applications will only run on Microsoft platforms, such as Windows Server or Windows XP.