I'm currently rewriting and updating articles here on this site that were published years ago. Currently working on the email category which had its fair share of Thunderbird extension reviews.
At least half of the extensions reviewed back then are no longer working properly in recent versions of Thunderbird.
Some were last updated in 2010 or even earlier than that and are simply no longer compatible with the email client even if you force compatibility.
While alternatives have been created for some, there are not alternatives available for most of those extensions.
The situation is less dire when you look at Firefox which can largely be explained by it having a larger userbase and it being more prominent in general.
It is unclear why developers decide to stop working on extensions and it needs to be said that this is not a phenomenon exclusive to add-ons for Thunderbird or Firefox.
Windows software for instance gets put on hold by developers as well.
One main difference however is that the software runs fine on newer versions of the operating system while extensions may not.
From what I was able to gather, reasons for stopping development include moving over to Chrome, losing interest in developing for Firefox or Thunderbird, and being fed up with requirements to update extensions to take changes in add-on APIs into account.
If you browse the extension repository you will stumble upon extensions that are not compatible with recent versions of Firefox or Thunderbird.
That's a usability issue right there. Existing users of either product on the other hand may notice that add-ons stop to work partially or completely after updates. We have seen this several times in the past already, for instance when Mozilla switched to the Australis interface or when old APIs were replaced by new ones.
The next big wave will hit when the new multi-process architecture is enabled in the Firefox browser.
Add-ons have always been one of the strengths of Firefox and Thunderbird. Back when the programs launched, they were the only ones offering this feature (Opera had only widgets back then which worked different) and users selected Mozilla products because of it.
Some users may still use Firefox because of one or multiple add-ons that they like and use that are only available for the browser in this form. NoScript is for instance one reason why I still use Firefox and not another browser.
Mozilla faces two issues currently
While 1) is relatively easy to accomplish, 2) is not. One option that may be available in some cases is to leave old code in for backwards compatibility.
Now You: Have you encountered add-ons in the past that stopped working?
Advertising revenue is falling fast across the Internet, and independently-run sites like Ghacks are hit hardest by it. The advertising model in its current form is coming to an end, and we have to find other ways to continue operating this site.
We are committed to keeping our content free and independent, which means no paywalls, no sponsored posts, no annoying ad formats (video ads) or subscription fees.
If you like our content, and would like to help, please consider making a contribution:
Ghacks is a technology news blog that was founded in 2005 by Martin Brinkmann. It has since then become one of the most popular tech news sites on the Internet with five authors and regular contributions from freelance writers.