Chris Beard, Mozilla's CEO, has posted an "open letter to Microsoft's CEO" about the way that Windows 10 handles default programs. He is complaining about "the Windows 10 upgrade experience that strips users of their choice" because Microsoft's Edge browser becomes the default after an "in place" upgrade.

Beard says: "we reached out to your team to discuss this issue. Unfortunately, it didn't result in any meaningful progress, hence this letter."

As Mozilla knows, Windows 10 users can change the defaults to whatever they want. However, Beard complains that "it now takes more than twice the number of mouse clicks," and that it's "confusing, hard to navigate and easy to get lost".

The letter includes a lightly veiled threat of anti-trust action in Beard's claim that "we are deeply disappointed to see Microsoft take such a dramatic step backwards." Microsoft has emerged from a decade of close US judicial supervision that followed its defeat in a major anti-trust trial prompted mainly by Netscape, Mozilla's predecessor. The US action was followed by a European case that resulted in a "browser ballot" being imposed, to force users to choose.

Microsoft announced its plans to change the default process in Windows 10 in a blog post on May 20, Announcing Windows 10 Insider Preview Build 10122 for PCs.

What sounds like a Microsoft attack on Firefox actually applies to all default programs. Microsoft says it did this to prevent users from suffering blizzards of prompts to change defaults, and to make traditional programs work in the same was as Windows Store apps. Microsoft claims that Windows Store apps, which are locked down and sandboxed, "could not invoke this prompt".

In the bad old days, Windows users suffered from "default wars" where programs tried to get themselves set as the default, and not all were beyond deception. Is it Beard, rather than Microsoft, "who wants to take a dramatic step backwards"?

In its May 20 blog post, Microsoft said: "We know your defaults matter to you. With Windows 10, all apps - both Classic Windows apps and Universal Windows apps - will be unable to invoke a prompt to change your defaults, only Windows. You remain in full control of your default experiences, while reducing some of the unwanted noise that multiple prompts can bring."

Beard's exaggerated complaint was parodied on Hacker News because of the Firefox update that changed users' default search engine. Animats wrote: "I am writing to you about a very disturbing aspect of Firefox 38.0.5. Specifically, that the update experience appears to have been designed to throw away the choice your customers have made about the Internet experience they want, and replace it with the Internet experience Mozilla wants them to have."

And later: "Sometimes we see great progress, where consumer products respect individuals and their choices. However, with the launch of Firefox 38.0.5 we are deeply disappointed to see Mozilla take such a dramatic step backwards."

Firefox forced a search engine switch to Yahoo, and after users reinstated their preference for (usually) Google, Firefox updates repeatedly changed it back.

This was, in fact, due to a bug, for which Mozilla apologized. However, it may still look like hypocrisy. As user byuu commented: "Yeah, this is the most 'pot calling the kettle black' article I've seen all month." He listed other complaints against Mozilla, including "no opt-out for Australis" and the bundling of Pocket and DRM web extensions.

Whether Beard is, in fact, right or wrong about the merits of the default settings, he does know that they also apply to Google and to many other companies who have so far refrained from writing whiny open letters about it.

Or, indeed, mounting a Twitter campaign about it.