Red Hat has called on Microsoft to promise publicly and in writing not to use software patents against users and individual developers of open source software.

"Let's leave customers out of this debate," Red Hat's deputy general counsel Mark Webbink told delegates at the LinuxWorld tradeshow in San Francisco. 

"If Microsoft has intellectual property that needs to be respected, come to Red Hat, come to Novell, but leave our customers out of it. There is no cost to Microsoft for doing this and it would prove their sincerity."

Webbink asked for a similar promise towards developers, pointing out that there is little sense in going after individual developers because they cannot afford to pay large legal settlements or licence fees anyway.

Microsoft has said in the past that it does not have a problem with open source as a technology, but Webbink argued that a public statement would give that claim credibility.

Software patents are a major problem not just for open source but for software in general, according to Webbink.

While patents serve a purpose in other industries such as pharmaceuticals, they are only used to "tax competition" in software, preventing competitors from entering the market. 

A single medicine, for example, is covered by a single patent, while software functions are often covered by multiple patents. Microsoft, for instance, owns 16 patents that cover the movement of the cursor.

"Innovation and patents are not the same thing," said Webbink. "Patents are problematic for our industry; they are there to constrain and slow down innovation."
Red Hat announced in June that it had started the creation of a patent commons that would allow patent holders to allow open source projects to use the patent.

Earlier this week at LinuxWorld OSDL launched an initiative aimed at building a library of software patents that have been pledged towards open source.