MNC's British Petroleum, Bank of America, US Army, Wal-Mart, Travelocity, ETrade, OfficeMax, ATScT, Google, Amazon, Yahoo, American Express...
Israeli government recently announced it's standardizing on Linux. China, Germany, and other countries have announced or are in the middle of migration plans.
Russia, United Kingdom and Brazil are exploring the OSS technology.
Argentina has experimented with moving entirely to Open Source model.
In the city of Europe, Munich is switching from Windows to Linux, and from Internet Explorer (IE) to Mozilla browser (CNet News 2004a).
HP has Global 500 customers running Linux on mission critical systems. IBM, SAP, Oracle and even Microsoft has used source code from a leading open-source operating system [Berkeley System Distribution or BSD] in its Windows 2000 and XP products and has acknowledged this on a public web site.