The issue at hand is trademarks. Mozilla Foundation software comes with trademarked names, and the use of those names is governed by the Mozilla Trademark Policy. If you want to distribute software called "Mozilla Firefox" or "Mozilla Thunderbird," you must adhere to a strict policy which includes signing an agreement with the Foundation and making almost no changes to the software. No extensions may be added, the list of search engines cannot be changed (they paid to be there, after all), etc. This highly-restrictive policy was never going to work with the Debian Project's needs.
Another approach is the "community edition" policy. A wider (but still narrow) range of changes is allowed, and the distributor can use the names "Firefox Community Edition." The commands can be called and . The Foundation maintains a veto right over uses of the "community edition" names, however:
So anybody distributing a "community edition" must live with the possibility of receiving a "takedown notice" from the Mozilla Foundation at any time. The Foundation's goals are certainly understandable:
Most readers will agree that a spyware-enabled Firefox is a bad idea, though whether purveyors of spyware will have much respect for trademarks is an open question.
The Debian Project insists on shipping nothing but free software, and freedom certainly includes the right to modify the code. Debian currently includes patches which may go beyond the trademark policy's guidelines - an extension manager which understands multi-user systems, for example. A strict reading of the community edition guidelines suggests that not even security patches could be distributed without prior approval from the Mozilla Foundation. The Debian Project certainly wants to be able to distribute modified versions of the code; the Project is also known for a close and literal reading of licenses. So the Debian developers are concerned about the whole trademark issue.
The Mozilla Foundation wants to work with Debian to get past these issues:
This arrangement could possibly include allowing Debian to apply its own patches to Firefox and Thunderbird and still use the community names. The Foundation seems to have a fairly high level of trust in Debian's ability to keep the quality up. Debian's users are another story, however:
So it looks somewhat like the Foundation would like to make a special policy exemption for Debian. The problem there is that Debian-specific licenses violate section 8 of the Debian Free Software Guidelines. Those guidelines apply to software licenses, not trademark policies, but the principle remains the same. The Debian Project is unlikely to accept a policy which does not extend to its users.
The discussion has quieted - it may have gone into a non-public mode - so it is difficult to say where things stand now. If an agreement cannot be found, Debian will still be able to distribute Firefox and Thunderbird - they are free software - but different names will have to be chosen. "Iceweasel" has been the working code name for this scenario; many other names have been suggested as well. This outcome would not be pleasing to any of the parties involved, however; one assumes it will be avoided if at all possible.
Mozilla is unlikely to be the last project that decides that it wants to
achieve some sort of quality control through its trademarks. That wish is
understandable, but it is also very much at odds with the spirit of free
software, which involves letting go of the code. One has to accept that
not everybody will have the same idea of what makes "high quality."
Incidents of free software projects being harmed by distribution of
poorly-done modifications have been rare, and, perhaps, are not worth the
worry that is being put into them here. Mozilla has done an outstanding
job of creating powerful and useful software; now, perhaps, the Foundation
may want to relax and trust its users just a little more.