Norwegian web browser maker Opera has filed a complaint with the European Commission claiming that Microsoft (NSDQ: MSFT) is abusing its dominant position by illegally tying its web browser Internet Explorer to its Windows operating system and by hindering interoperability by not following accepted web standards, reports Digital Lifestyles.

SEE ALSO: Microsoft Loses EC Anti-Trust Appeal; $680 Million Windows Media, Server Fine Upheld

What makes the complaint unusual is Opera’s claim that by not making Explorer interoperable, Microsoft shifts that burden onto web site developers, who have to ensure that their sites work across all the various browsers on the market. If a browser plays by different standards rules, it makes it much more difficult, expensive and time consuming for the developer to create a site. Obviously, developers will build sites to the most popular browser at the expense of smaller ones.

Opera CEO Jon von Tetzchne told Digital Lifestyles that while he didn’t have any direct indication from the EU that Opera’s complaint would be successful, he noted that after the company saw the EC’s ruling on the Media player, they believed they “stood a good chance.” The EC slapped a 497 million euro (£344m) fine on Microsoft after it found the company had stifled competition by bundling its Media Player with Windows. In September, Microsoft lost its final appeal in the case. Von Tetzchne added that as browsers are placed on more devices, “a unified web is important.”