15 April 2004 Microsoft is under pressure from antitrust authorities in the US to disclose more of its operating system source code, to enable rival application developers to write better software for Windows.

The US Justice Department is keen to enforce the protocol licensing plan outlined in the 2001 antitrust ruling against the software giant. Microsoft has agreed to work with the Justice Department to allow competitors greater access to its server protocols, according to a report filed in a US federal court.

But complaints about the standard of the accompanying technical documentation prompted the report’s authors to recommend “substantial revision in order to ensure that it is usable by licensees”.

Only a small number of companies (including Sun Microsystems and AOL) have licensed the protocols and most of these are for niche products that would not present a serious challenge to Microsoft’s monopoly, which is what regulators hoped to achieve by the plan. This has led a Massachusetts court to challenge the 2001 ruling.

The Justice Department’s decision is surprising given its hostility to the European Commission’s ruling against Microsoft, which along with a $600 million fine and an order to include rival media player software with its Windows operating system, has also told Microsoft to make more of its server code available to rival software developers.