Rịba ama amaokwu a dị n'okpuru ma zaa ajụjụ ahụ mgbe e mesịrị n'otu asụsụ ahụ dị ka amaokwu ahụ:  Passage: N'August 2000, Microsoft, Hewlett-Packard, na Intel rụrụ ọrụ iji mee ka Common Language Infrastructure (CLI) na C #. Ka ọ na-erule Disemba 2001, ha abụọ kwadoro ụkpụrụ Ecma International (ECMA). Òtù International Organization for Standardization (ISO) sochiri na Eprel 2003. Ụdị ọkọlọtọ ISO dị ugbu a bụ ISO/IEC 23271:2012 na ISO/IEC 23270:2006.Ọ bụ ezie na Microsoft na ndị mmekọ ha nwere patent maka CLI na C #, ECMA na ISO chọrọ ka patent niile dị mkpa maka mmejuputa dị na "okwu ezi uche dị na ya na nke na-abụghị nkewa". Ụlọ ọrụ ndị ahụ kwetara imezu ihe ndị a, ma mee ka e nweta ihe ndị ahụ e mepụtara n'efu. Otú ọ dị, nke a emetụtaghị akụkụ nke.NET Framework nke ECMA-ISO na-ekpuchi, nke gụnyere Windows Forms, ADO.NET, na ASP.NET. Ihe nchọpụta nke Microsoft nwere na mpaghara ndị a nwere ike ime ka ndị na-abụghị Microsoft mejuputa usoro zuru ezu.Na Ọktọba 3, 2007, Microsoft kwupụtara na koodu isi maka.NET Framework 3.5 ọbá akwụkwọ ga-adị n'okpuru Microsoft Reference Source License (Ms-RSL). Ebe nchekwa koodu isi wee dị na ntanetị na Jenụwarị 16, 2008 ma gụnye BCL, ASP.NET, ADO.NET, Windows Forms, WPF, na XML. Scott Guthrie nke Microsoft kwere nkwa na a na-agbakwunye ọba akwụkwọ LINQ, WCF, na WF.  Ajụjụ: Olee mgbe e mere ha?
Disemba 2001