No Microsoft browser rival would comment on, much less confirm, that it reported the omission of the browser ballot to European antitrust regulators.
All three of Microsoft's Windows browser competitors -- Google, Mozilla and Opera Software -- declined to comment yesterday on a report by the U.K.'s Financial Times ( registration required) that used unnamed sources to say Google and Opera had independently or in combination tipped off the European Commission last summer.
On Wednesday, the Commission hit Microsoft with a $732 million fine for shirking a 2009 agreement that required it to offer Windows users a choice of alternate browsers.
"It goes without saying that settlements can only work if the commitments are scrupulously complied with," said Joaquin Almunia, the head of the EU's antitrust agency, on Wednesday. "They must do what they have committed to or face the consequences."
According to Almunia, neither the Commission nor Microsoft -- which had been left to police itself -- was aware that the browser choice screen was AWOL until a third party reported the oversight.
The Commission has repeatedly declined to name the complainant.
The choice screen, also called the "browser ballot," was not shown to approximately 15.3 million users running Windows 7 Service Pack 1 (SP1) for more than a year, from May 2011 until July 2012, when the complaint was filed.
Some critics have found it hard to believe that neither Microsoft nor the Commission realized the ballot was missing for over a year, and concluded that it was no accident, as Microsoft has claimed.
"You can't say it's accidental for 15 months," argued Robert Lande, a law professor at the University of Baltimore and director of the American Antitrust Institute, in an interview this week. "Microsoft says it was a technical glitch, okay, one month, I understand, you left it out of a batch. But not for 15 months. That doesn't look like an accident to me."
Whether accidental or not, Microsoft did benefit while the ballot screen was truant, according to data from Irish analytics company StatCounter.
For the 15 months from May 2011 until July 2012, inclusive -- the period in which the Commission said there was no ballot displayed in Windows 7 SP1 -- Microsoft's Internet Explorer lost an average 0.5 of a percentage point each month in European usage share.
While IE continued to lose ground during that time, it did so at a slower rate than either before or after: In the 15 months preceding May 2011, IE lost an average 0.64 of a percentage point each month. During the seven months since July 2012, IE lost 0.58 of a percentage point each month.
While the difference in the figures before, during and after may seem small, when represented as percentages they are more substantial: IE's average monthly decline slowed 22% when the ballot was on holiday, then accelerated by 16% after its return.
The missing browser choice screen also coincided with a significant drop in Firefox's European usage share.
In the 15 months when the ballot was absent, Firefox lost an average 0.47 of a percentage point each month, more than double the 0.2 of a point it fell in the 15 months prior, and nearly triple that of the 0.16 of a percentage point in the seven months after the screen was restored.
Mozilla has already made a case that the omitted ballot impacted Firefox downloads in Europe. Last October, after the Commission formally charged Microsoft with violating the 2009 settlement, Mozilla said the missing browser choice screen cost it an estimated 8.8 million downloads.
At the time, Opera, which filed the 2007 complaint that triggered the Commission's original investigation, also chimed in, saying its downloads had doubled in the months after the screen returned to Windows 7 SP1.
By StatCounter's tracking, the disappearance of the ballot was concurrent with a six-fold jump in Opera's average monthly loss in Europe compared to the 15 months prior. In the seven months after the screen's restoration, however, Opera lost twice as much each month as it had during the ballot's absence.
Google's Chrome was seemingly unaffected, with average European monthly gains during the ballot's holiday of 0.84 of a percentage point, more than either the 0.82 of a percentage point average increase during the 15 months before the ballot vanished or the 0.60 of a percentage point average climb in the seven months since it was again imposed.
Of course, it's possible that the ups and downs of Europe's browser shares before, during and after the ballot's absence were not connected with the choice screen.
Clearly, the ballot's sabbatical did not change the fortunes of any browser, even IE's. StatCounter's numbers clearly show that the trends established before May 2011, when the ballot dematerialized, continued: IE, Firefox and Opera have all been losing share in Europe for years, while Chrome has been the beneficiary, picking up enough share there to push it into the No. 1 spot last summer.
U.S. metrics firm Net Applications, which also measures browser share -- albeit using a different methodology -- declined to provide granular data for Europe similar to what StatCounter offers publicly. But the two data points that Net Applications did share -- the standings in Jan. 2010 and Feb. 2013 -- showed the same general trends: IE, Firefox and Opera lost half or more of their share between the two dates, while Chrome's jumped nearly six-fold.
So who tipped off the EU? No one knows, and no one's talking.
All three browser rivals, however, had motive. Opera was the one that first complained about IE's ties to Windows, Mozilla has been the most vocal in opposing Microsoft's browser moves, and Google has been locked in a multi-front fight with Microsoft over everything from mobile patent licensing and enterprise applications to search and online email.
There may never come a Clue moment, when someone could claim it was "Colonel Mustard in the library with the knife."
Lande, however, had his suspicions. "It seems to me absolutely impossible that Google wouldn't have noticed," he said in a earlier interview. "Google hates Microsoft with a passion, and they're one of the most sophisticated companies on the planet. And they have lawyers in Brussels."
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer, on Google+ or subscribe to Gregg's RSS feed. His email address is firstname.lastname@example.org.
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