.NET Framework - Wikipedia
https://en.wikipedia.org/wiki/.NET_FrameworkMicrosoft .NET Framework v4.5 logo In November 2014, Microsoft also produced an update to its patent grants, which further extends the scope beyond its prior pledges. Prior projects like Mono existed in a legal grey area because Microsoft's earlier grants applied only to the technology in "covered specifications", including strictly the 4th editions each of ECMA-334 and ECMA-335.