Microsoft will today cite US evidence to prove that it is complying with a European anti-trust ruling that could cost it €2 million a day. It will also argue that the ruling was not precise enough in the first place.

At a hearing with the European Commission today, Microsoft will dispute the Commission's accusation that it has not complied with the 2004 ruling, in a bid to stave off possible daily fines of €2 million.

The EU has demanded that Microsoft level the playing field by allowing competitors to license the communications protocols for its workgroup server software. This would allow them to build products that work well with Windows and compete with other Microsoft products.

Microsoft will cite six satisfied customers of a similar licensing programme demanded by US regulators after a similar antitrust case there, to prove that it is complying. EMC, for instance, has used Microsoft-provided documentation "as a reference guide to fill in gaps in EMC's existing implementation of the file server protocols, particularly the SMB protocol," - according to an EMC statement provided by Microsoft.

The other companies include storage vendor Network Appliance, videoconferencing vendor StarBak, and video-on-demand vendor Tandberg Television.

However, it is not clear that the programmes are equivalent. The European programme includes 55 protocols, 46 of which are also part of the US programme, according to Microsoft.

It was not immediately clear, however, if the protocols are documented in the same way in Europe, and what level of documentation is required in the first place.

"What we're saying is that the documentation has been created to the same standard [as the US programme]," said Microsoft spokesman Tom Brookes said. Microsoft also said it needs "concise and consistent information" about what the EC requires.

Industry analysts were impressed by the documentation provided, but echoed Microsoft's doubts about the level of definition required by the ruling. Several analysts saw the European documentation in London recently, in an effort that was "partly public relations but also to get our view," said Gary Barnett at UK analyst company Ovum.

"I was really surprised when I saw the documentation they had put together. I was expecting, based on what I had heard, something much less complete. But I'd have to say - with the caveat that this is based on the two or three examples they showed us - that it was quite impressive," he said.

One of the problems, he said, is that the usefulness of the documentation depends partly on who it's intended for.

"Should [Microsoft] be providing a document that would allow a first-year computer science student to create an entire protocol, or are they entitled to assume that if you're setting up business to implement the protocols that you'll hire a few Microsoft platform Jedis?" he asked.

"That's not clearly enumerated, and it's the fault of the European Union for not making it clear, and it's also Microsoft fault for agreeing to comply with such a request."

James Governor, an analyst at RedMonk, who also saw the documentation, said "it's a system that kind of works." The problem, he said, is that companies don't want to have to become Microsoft licensees in order to make competing products, and the fees Microsoft is proposing for the licensing program are too high for small companies.

Microsoft had been scheduled to hold a press conference early Thursday afternoon, but it cancelled it late in the morning, saying that a Commission officer had requested they "respect the confidentiality of the process".