Are most of the existing add-ons being sacrificed due to adding support for WebExtension?

Magnus Melin mkmelin+mozilla at
Wed Nov 22 21:38:51 UTC 2017

I think there are at least two reasons it hasn't been announced: that 
it's coming has been touted from Mozilla for a long time, so that 
traditional add-ons would cease to work on Firefox is simply not news. 
Second, what the implications for Thunderbird are has not been clear, or 
how feasible supporting traditional add-ons will be for 59 and beyond.

But sure, bore blog posts would be good.


On 22-11-2017 17:45, Eric Moore wrote:
> "No one has made any decision, the facts are imposed on us by changes in
> Mozilla-core. All people actively involved with the development of TB
> were aware of the never-ending bustage coming in from Mozilla-core."
> Thank you for your detailed reply.
> I had followed the earlier discussions about whether or not to fork in 
> the tb-planning mailing list, and had been left with the impression 
> that a distinction was made between forking Gecko as a long term 
> solution, and temporarily deciding not to use the version 57 and 59's 
> toolkit while trying to develop Thunderbird++ as soon as possible.
> My concern is that there is a serious disconnect with what users want 
> and expect. They are not expecting most of the add-ons to break. My 
> impression is that they expect Thunderbird to somehow avoid following 
> the path Firefox took. There is also a lot of concern about the future 
> of Thunderbird. Many are well aware of Thunderbird's problems, but 
> nobody is telling them what to expect, or offering them any hope. 
> There is just silence.
> I'm seeing more users decide not to upgrade to the latest version in 
> order to keep their favorite add-ons working. I suspect many would be 
> comfortable temporarily living with the potential risks of a out of 
> date toolkit if that is what it takes to not lose most add-ons. 
> Especially those that select "view -> display attachments inline".
> What troubles me is if a decision was made by "the Council, the 
> Engineering Steering Committee and the developer community" why wasn't 
> a post made about it on the Thunderbird blog explaining what they are 
> thinking of doing, why its necessary, and what the implications are. 
> Especially "If we determine the only viable path forward is to frame 
> everything in an embedded WebExtension, we might consider automating 
> this change for all Thunderbird add-ons." (from Philipp's post).
> _______________________________________________
> tb-planning mailing list
> tb-planning at

More information about the tb-planning mailing list