New York Stock Exchange -- "Here at SIAC and NYSE Python is recognized by management to give results that other languages just can't achieve." See this email and this summary.
Google -- "Python has been an important part of Google since the beginning, and remains so as the system grows and evolves." See quote on this page.
Yahoo -- Used at least in Yahoo People Search, Yahoo Yellow Pages, and Yahoo Maps.
Nasa -- "NASA is using Python to implement a CAD/CAE/PDM repository and model management, integration, and transformation system," see quote on this page.
United Space Alliance -- "We achieve immediate functioning code so much faster in Python than in any other language that it's staggering." More.
Philips -- "Python [is] a robust and productive way to write, debug, and maintain complex systems." More.
Industrial Light & Magic -- Used extensively on Star Wars I and II and other films. More.
Disney -- Used in feature length animation. More.
AstraZeneca -- "As a result of using Python, we were able to quickly and easily develop a great tool." More.
Compaq -- New Windows XP systems ship with a hidden Python 2.2 installation used for installation and configuration.
Verity (formerly Infoseek) -- "[With Python], the Verity Ultraseek development team has been flexible and responsive in developing, implementing and improving features according to customer feedback." More.
Rackspace -- "Python has dramatically improved development processes for the CORE project." More.
Tribon -- "Python has proven to be a perfect tool for creating an API to existing applications." More.
US Navy -- "A Zope-based solution ... greatly reduces the time required to implement engineering changes." More.
Journyx Timesheet -- "Python has been an important competitive advantage for us." More.
Paint Shop Pro 8 -- From the Readme file: "PSP 8 has a full blown scripting engine, based on the Python programming language."
HomeGain -- "Python supports [our] short time-to-market philosophy". See full quote on this page.
Many More Python Users
Another Python Users List