Microsoft rivals have complained to European Union (EU) antitrust regulators that the software giant's plan to add a so-called web browser ballot screen to Windows doesn't do enough to level the playing field. The complaints—which were widely expected—come in the wake of a request for feedback by the European Commission (EC).

"The ballot screen requires the user to confirm and answer threatening and confusing warnings and questions," says European Committee for Interoperable Systems (ECIS) attorney Thomas Vinje. "Microsoft has cunningly found a way to accept the commission's suggestion of a ballot screen but to do so in a way that will be entirely ineffective."

To be clear, the ECIS is a trade group that was created to oppose Microsoft. It counts among its members Opera, the company that started the EU browser investigation, as well as long-time Microsoft rivals Adobe, IBM, Oracle, RealNetworks, Red Hat, and Sun Microsystems.

But the ECIS isn't the only group complaining about the ballot screen. Number-two browser maker Mozilla Corporation has asked for "modifications and clarifications" to the plan, though that company does support the notion of a Windows-based browser ballot screen.

Companies such as Opera and Mozilla are wise to seek as many concessions as they can. But Microsoft's decision to allow a ballot screen in its core and still-dominant Windows product is unprecedented. It's unclear whether the company will attempt to fight any attempts to make this screen friendlier to the competition.