Standardization and licensing

In August 2000, Microsoft, Hewlett-Packard, and Intel formed to assimilate CLI and the C# programming language. By December 2001, both were ratified ECMA standards (ECMA 335 and ECMA 334). ISO followed in April 2003 - the accepted adaptation of the ISO standards are ISO/IEC 23271:2012 and ISO/IEC 23270:2006.1415

While Microsoft and their ally authority patentscitation bare for the CLI and C#, ECMA and ISO crave that all patents capital to accomplishing be fabricated accessible beneath "reasonable and non-discriminatory terms". In accession to affair these terms, the companies accept agreed to accomplish the patents accessible royalty-free.citation needed

However, this does not administer for the allotment of the .NET Framework which is not covered by the ECMA/ISO standard, which includes Windows Forms, ADO.NET, and ASP.NET. Patents that Microsoft holds in these areas may avert non-Microsoft implementations of the abounding framework.16

On 3 October 2007, Microsoft appear that abundant of the antecedent cipher for the .NET Framework Base Class Library (including ASP.NET, ADO.NET, and Windows Presentation Foundation) was to accept been fabricated accessible with the final absolution of Visual Studio 2008 appear the end of 2007 beneath the aggregate antecedent Microsoft Reference License.1 The antecedent cipher for added libraries including Windows Communication Foundation (WCF), Windows Workflow Foundation (WF), and Accent Chip Query (LINQ) were to be added in approaching releases. Being appear beneath the non-open antecedent Microsoft Reference License agency this antecedent cipher is fabricated accessible for debugging purpose only, primarily to abutment chip debugging of the BCL in Visual Studio.