Open...And Shut Apparently, one can have too much freedom.

That's one takeaway from The Wall Street Journal's revelation that Mozilla killed a new Firefox tool, which would have limited advertisers' ability to track users across the web, allegedly under pressure from the advertising industry. Sure, Mozilla is a nonprofit and arguably not under the thumb of anyone, but it does get the vast majority of its revenue from advertising-funded Google, and so must be under a certain amount of pressure - subconscious or otherwise - to cater to advertisers' needs.

However, Mozilla vice president Mike Shaver disputes the allegation that Mozilla buckled under pressure, and in the process gives a clue as to whose interests Mozilla serves:

I wouldn't say we are under pressure from advertisers. They are a big part of the economics of the web. We want to understand what their needs are.

Mozilla has also long adhered to its mission of "promot[ing] openness, innovation, and opportunity on the web." Normally, we assume this mission applies only to end-users like you or I as we browse the web, and that "unlimited freedom" must be the right way to serve such interests.

Maybe. Maybe not.

It's quite possible - indeed, probable - that the best way for Mozilla to fulfill its mission is precisely to limit the openness of the web. At least a bit. Why? Because end-users aren't the only ones with rights and needs online, a point Luis Villa elegantly made years ago.

It's not a one-way, free-for-all for end-users. Advertisers, developers and enterprises who employ end-users among others all factor into Mozilla's freedom calculus. Or should.

The freedom fighters of the open-source movement may howl in rage at this, but there's good precedent for Mozilla's stance. Richard Stallman, for starters.

Stallman has long criticized the more pragmatic half of the open-source community for its somewhat libertarian approach to licensing, a la Apache and BSD. Yet in an age of web-delivered software-as-services, an age that treats Stallman's GPL with absolute indifference, Stallman expressly demurred from baking in a broader definition of "distribution" into version three of the GPL. My sources suggest that this was a direct consequence of Google applying pressure to the Free Software Foundation.

When then-general counsel of the FSF, Eben Moglen, gave a keynote at the Open Source Business Conference in 2007, he was asked about the FSF's decision not to close the so-called "ASP loophole" in the GPL that allowed companies like Google to heavily modify GPL code and distribute it as a service, without contributing commensurately back. In early drafts of GPLv3, the FSF had defined "distribution" to effectively bar network-based software distribution, but in the final draft it was purged, and then whimpered its way into the GPL's ugly stepchild, Affero GPL.

Moglen danced around the issue and finally gave an answer much like Mozilla's: there are different kinds of users of software on the web and the FSF had to balance the needs of end-users with intermediate users like Google.

If that sounds like a reasonable position, it's because it is. But many in the free-software camp are so hell-bent on freedom that they forget that it's a much more nuanced concept than they usually suspect.

Red Hat is another good example of this. One of the big challenges of open-source software has been finding successful revenue models to pay for its development. This is why most open-source software development - at least, within the big projects like Linux - is done by paid developers who are employed by companies selling proprietary software or hardware.

Red Hat is the exception to this rule, and looks set to top $1bn in annual revenue in 2011. But even Red Hat has managed this impressive feat by taking a "mostly open" approach to its licensing/contracting strategy. Sure, you can get the raw source code from Red Hat, just as CentOS does. But if you want it packaged and easily delivered, you're going to have to sign up as a customer.

Some - including individuals within my own company, Canonical - call this "proprietary Linux." I call it smart business, and a fair trade-off, one that enables Red Hat to contribute nearly double the amount of code to the Linux kernel than any other company while minting nearly $1bn selling otherwise free code.

That's the tradeoff. Such tradeoffs may drive purists like Henrik Ingo from MariaDB mad, but they draw widespread, mainstream user (and developer) adoption.

Mozilla, then, isn't just doing itself a favor by carefully considering how to implement do-not-track functionality in Firefox. It's doing us all a favor: users, advertisers, developers, and more. ®

Matt Asay is chief operating officer of Ubuntu commercial operation Canonical. With more than a decade spent in open source, Asay served as Alfreso's general manager for the Americas and vice president of business development, and he helped put Novell on its open-source track. Asay is an emeritus board member of the Open Source Initiative (OSI). His column, Open...and Shut, appears every Friday on The Register.