Computer programmers are urging politicians in California to use more open source software. Delegates attending the Linux World Conference in San Francisco want California to adopt the Digital Software Security Act.
The proposal has been drawn up by professionals in the open source community to address Microsoft's dominance of the global software industry.
The aim is to require state agencies to buy open source alternatives to programs like Microsoft's Windows.
Open source software can be downloaded from the Internet for free and doesn't require users to pay licensing fees.
Linux is the most popular example and is increasingly being used by government agencies and corporations to run databases and manage email systems. Research firm ADH Brown Associates recently estimated there are about 20 million users worldwide.
The Act's co-author Michael Tiemann, who is chief technology officer at Red Hat, told delegates: "Government and monopolists want to take away our right to write software and use computers as we want to use them. Open source is the true spirit of democracy, and we must preserve it."
But the Computing Technology Industry Association has strongly criticised the notion that a state should favour open source above proprietary software.
The Washington-based trade group said the proposal would stifle innovation in corporate America and cause "unintended repercussions for California, its industry and its citizens".
A Microsoft spokesman declined to comment on the Act, but said the company supported the CTIA's position.