Though some believe that technologies used in .NET were originally developed by Microsoft as their version of the Java platform, the truth is that many of the teams working on .NET initially set out to create COM+ 2.5. Other departments were also improving other Microsoft technologies; the web Server department was creating ASP 4.0 and the Microsoft distributed computing departments were creating what was called "Next-Generation Web Services". The work from the various departments merged into one system now called .NET.

When Microsoft decided to end their future use of Sun's Java technologies in 1998, the existing Microsoft J++ (Java) product was transformed into the beginnings of the .NET project. Code from the .NET Common Language Runtime (CLR) was said to have come from Colusa Software's OmniVM, which Microsoft acquired on March 12, 1996. Despite the rumors, the Microsoft CLR is not truly comparable to the Java VM as the CLR is a common language runtime, not a common platform runtime as the Java VM is. The CLR is actually the Microsoft implementation of the ECMA CIL standard. While Java applications can be written for many different platforms in only one language, .NET applications can be written in many different languages for, currently, only one operating-system platform (though many hardware platforms).


While the original model of .NET was that of a general foundation (.NET framework) with three primary pillars (ASP.NET, Windows, and Web Services), the model for .NET 2.0 is that of a foundation for Microsoft's next generation platform known as WinFX, which is the unification of Microsoft development technologies into one programming model. WinFX is also the replacement for the longlived Win32 API introduced in the early 1990s. The FX in WinFX is the abbreviation for the .NET Framework thus giving .NET the tall standing of being the foundation of the majority of future Microsoft-based development, higher or lower level.