More than 60 data experts staged a rare and noisy street demonstration in downtown Oslo to protest against Microsoft's new  document format as an international standard.

The International Standards Organisation voted in favor of using Microsoft's Office Open XML, or OOXLM, format as a world standard, despite claims by opponents that it locks out competitors and forces people to keep buying Microsoft products.

The  Oslo protest was called by Steve Pepper, who stepped down as Chairman of the Standards Norway Committee after he was outvoted in a decision for Norway to support Open XML.

"People shouldn't have to pay money to Microsoft to be able to read my documents," he said.

He said there was already a good ISO standard, called OpenDocument Format, or ODF, that allows documents to be opened by programs from different software companies.