The Free Software Foundation has launched a campaign to warn consumers and companies off of buying into Windows 7, Microsoft's next operating system, due a general release in late October of this year.

The "Windows 7 Sins" campaign makes the case against Microsoft and proprietary software and outlines areas "where proprietary software in general and Microsoft Windows in particular hurt all computer users: invading privacy, poisoning education, locking users in, abusing standards, leveraging monopolistic behavior, enforcing Digital Restrictions Management, and threatening user security".

The Foundation is also sending letters to the CEOs of Fortune 500 companies. The letter warns "Windows 7 decision makers" about the "lack of privacy, freedom, and security" they will suffer if they go down the Microsoft route and advocates open source software instead.

Although Windows 7 is the focus of this campaign, the Foundation is actually against all kinds of proprietary software:

Campaigns manager Matt Lee says: "With, we hope to make businesses and computer users aware of the growing dangers of proprietary software from both Microsoft and other companies such as Apple and Adobe. With the release of Microsoft's updated operating system, business leaders have the opportunity to escape to freedom and join a growing list of leaders who understand that sinking money and time into proprietary software is a dead-end inconsistent with their best interests".