Standardization and Licensing
In August 2000, Microsoft Corporation, Hewlett-Packard and Intel Corporation co-sponsored the submission of specifications for C# as well as the Common Language Infrastructure (CLI) to the standards organization Ecma International. In December 2001, ECMA released ECMA-334 C# Language Specification. C# became an ISO standard in 2003 (ISO/IEC 23270:2003 - Information technology — Programming languages — C#). ECMA had previously adopted equivalent specifications as the 2nd edition of C#, in December 2002.
In June 2005, ECMA approved edition 3 of the C# specification, and updated ECMA-334. Additions included partial classes, anonymous methods, nullable types, and generics (similar to C++ templates).
In July 2005, ECMA submitted the standards and related TRs to ISO/IEC JTC 1 via the latter's Fast-Track process. This process usually takes 6–9 months.
The C# language definition and the CLI are standardized under ISO and Ecma standards that provide reasonable and non-discriminatory licensing protection from patent claims. However, Microsoft uses C# and the CLI in its Base Class Library (BCL) that is the foundation of its proprietary .NET framework, and which provides a variety of non-standardized classes (extended I/O, GUI, Web services, etc.). Some cases where Microsoft patents apply to standards used in the .NET framework are documented by Microsoft and the applicable patents are available on either RAND terms or through Microsoft's Open Specification Promise that releases patent rights to the public, but there is some concern and debate as to whether there are additional aspects patented by Microsoft that are not covered, which may deter independent implementations of the full framework.
Microsoft has agreed not to sue open source developers for violating patents in non-profit projects for the part of the framework that is covered by the OSP. Microsoft has also agreed not to enforce patents relating to Novell products against Novell's paying customers with the exception of a list of products that do not explicitly mention C#, .NET or Novell's implementation of .NET (The Mono Project). However, Novell maintains that Mono does not infringe any Microsoft patents. Microsoft has also made a specific agreement not to enforce patent rights related to the Moonlight browser plugin, which depends on Mono, provided it is obtained through Novell.
In a note posted on the Free Software Foundation's news website in June 2009, Richard Stallman warned that he believes that "Microsoft is probably planning to force all free C# implementations underground some day using software patents", and recommended that developers avoid taking what he described as the "gratuitous risk" associated with "depend on the free C# implementations". The Free Software Foundation later reiterated its warnings, claiming that the extension of Microsoft Community Promise to the C# and the CLI ECMA specifications would not prevent Microsoft from harming free implementations of C#, because many specific Windows libraries included with .NET or Mono were not covered by this promise.
Read more about this topic: C Sharp (programming Language)