NASA
The National Aeronautics and Space Administration is an independent agency of the executive branch of the United States federal government responsible for the civilian space program, as well as aeronautics and aerospace research.

Tesla Motors
Now a days Tesla is every where in news. What's so special ?
Yes, they are the leading automotive and energy storage company that designs, manufactures, and sells luxury electric cars, electric vehicle powertrain components, and battery products.

UN - United Nations
The United Nations is an intergovernmental organization tasked to promote international cooperation and to create and maintain international order.

Pfizer Inc.
Pfizer Inc. is an American pharmaceutical corporation headquartered in New York City, with its research headquarters in Groton, Connecticut.

GE - General Electric
General Electric (GE) is an American multinational conglomerate corporation incorporated in New York and headquartered in Boston, Massachusetts. As of now, the company operates through the following segments: Aviation, Current, Digital, Energy Connections, Global Research, Healthcare, Lighting, Oil and Gas, Power, Renewable Energy, Transportation, and Capital which cater to the needs of Financial services, Medical devices, Life Sciences, Pharmaceutical, Automotive, Software Development and Engineering industries.

Twenty-First Century Fox
Twenty-First Century Fox Inc. is an American multinational mass media corporation based in New York.

SpaceX
Space Exploration Technologies Corporation is an American aerospace manufacturer and space transport services company with its headquarters in Hawthorne, California, USA

Oscars
The official website of Academy awards powered by Drupal.

Time Warner
The mother website of Time warner runs on a Drupal engine

Johsnson & Johsson
We all had a very good memories with JnJ and their mother website is powered by Drupal.

Indian Government
Government of India official website is powered by Drupal 7 !

Qualcomm
Qualcomm is an American multinational semiconductor and telecommunications equipment company that designs and markets wireless telecommunications products and services.

AMD
Advanced Micro Devices, Inc. is an American multinational semiconductor company based in Sunnyvale, California, United States, that develops computer processors and related technologies for business and consumer markets.

The Weather Company - weather.com
The Weather Company is a weather forecasting and information technology company that owns and operates weather.com, intellicast.com, and Weather Underground.

UNESCO
The United Nations Educational, Scientific and Cultural Organization is a specialized agency of the United Nations based in Paris. UNESCO's aim is "to contribute to the building of peace, the eradication of poverty, sustainable development and intercultural dialogue through education, the sciences, culture, communication and information".

The Royal Family
British Royal family's official website; Royal.uk is visited by an average of 12 million people each year. And it's powered by Drupal

This isn't final one. Day by day companies switching to Drupal.
We will keep updating this list. Stay tuned.