Microsoft's compliance with the 2004 EU anti-trust ruling offering some good news to open source developers and users.

The agreement will make it much easier for commercial and especially open source providers to create products that work with Microsoft products. As a result, Microsoft will no longer be able force itself upon new markets by offering a level of integration that isn't available from competing vendors.

Under terms of the ruling, Microsoft will publish an irrevocable pledge not to assert any patents it may have over the interoperability information against non-commercial open source software development projects.

Commercial projects will be able to safeguard themselves against interoperability patent claims at a reduced royalty fee of 0.4 per cent of revenues. Microsoft had initially demanded a 5.95 per cent royalty rate.

Joshua Gay, a campaigns manager with the Free Software Foundation, welcomed the patent pledge towards non-commercial open source applications as "great news ". He declined further comment because he hadn't had the time to study the details of Monday's news.

Microsoft on Monday agreed to make major changes to the way it licenses interoperability information and patents on interoperability information. European Commissioner for Competition Policy Neelie Kroes had demanded a reduction in licensing fees as well and wanted Microsoft to make interoperability information available to open source source developers.

"Microsoft will now do so, with licensing terms that allow every recipient of the resulting software to copy, modify and redistribute it in accordance with the open source business model," Kroes said in a statement.

"I told Microsoft that it should give legal security to programmers who help to develop open source software and confine its patent disputes to commercial software distributors and end users. Microsoft will now pledge to do so."

In addition to the royalty-free licence for open source developers, Microsoft also reduced the fees it charges commercial vendors of both closed and open source software. The developer will cut its patent licensing fees for commercial vendors from 5.95 per cent to 0.4 per cent of software revenues.

Fees for Microsoft's non-public interoperability information will be reduced to a one-time payment of €10,000. Microsoft had originally demanded 2.98 per cent of revenues.

Companies that dispute the validity of Microsoft's patents only have to pay the one-time interoperability fee.