The addon was abandoned by its author because Mozilla was making major changes to the addon API at the time. Extensions used to have carte blanche to change the browser, which was a security risk, not to mention it made threading/parallelizing the browser hard. The new extension API removed a lot of that freedom. After the API change, it wasn't possible (and might still not be) to develop a useful tab groups addon with the new API, so the author ceased development.

I can't imagine Mozilla crippling the addon API to the point where it can't grab data off an RSS feed and display it.

> Extensions used to have carte blanche to change the browser, which was a security risk …

I don't buy that. It's my browser running on my computer, it's my choice whose code I choose to run on it.

If, say, emacs or vi had this kind of handholding, neither one would be much more than a text editor.

Emacs and vi are used by programmers. Browsers are used by nearly every single person on the Internet. The threat model is completely different.

Time for a developers only Browser! Anyone wants to grab that? :)

Qutebrowser and next browser are both quite programmer-focused. They are WebKit based, however.

qutebrowser uses QtWebEngine, which is based on Chromium/Blink - I wouldn't call that WebKit anymore ;-)

I was probably wrong about next too, then. Still, they both hail from the Steve Jobs school of blurry fonts, which is all any sane person tries to avoid in a web browser ; )

Emacs or vi don't handle potentially malicious third-party code...

Sure they do. That's what extensions are.

That’s like saying everyone is at risk of bear attacks because a few people in rural areas do get attacked. Yes, extensions exist but when was the last time someone clicked on a link in an email and installed an emacs extension? That happens daily to thousands of web users because the population is so many orders of magnitude greater.

> The replacement that is compatible with the new form of extension isn't able to unload the tabs, just hide them, which undoes most of the performance benefits.

I believe this information is out of date. Firefox 58 brought extension developers the ability to unload tabs: https://bugzilla.mozilla.org/show_bug.cgi?id=1322485

And Totally Not Panorama takes advantage: https://addons.mozilla.org/en-GB/firefox/addon/basic-panoram...

> Mozilla did the same with tab groups, then the addon was abandoned.

Wouldn't that indicate that the extension was not that widely used, and as such Mozilla were correct in removing it from the central codebase?

“Not that widely used" is an incredibly elastic term. When you axe twenty "5% features" your worst case is offending 100% of your users.

Which can be worth it depending on what you trade it for. I really liked the tab group feature but the new extension API is vastly more secure and can (probably) be extended to allow for most addons.

At Mozzila they need to prioritize many different things and I can understand how a constant push to make the browser leaner is foundamental. (especially in cases like RSS feeds)

It's true that it wasn't widely used, but it seems as if Mozilla did their best to make it that way. It wasn't exposed to the user by default, but instead was hidden as something you could get to by the toolbar customization screen, so you had to modify the toolbar to even get access to the feature.

I don't think most people even knew it was there.

Just like RSS in modern versions, and just like tab groups they will be removing it too.

FWIW, Tree Style Tab solved tab groups (and more) for me.

I wish tab handling had a first-class API in Firefox, so that different tab managers could interact with the default tab menu, etc.

> FWIW, Tree Style Tab solved tab groups (and more) for me.

Yes, but I don't really want tree-styled tabs, I want tab groups :P The interface is vastly different.

Also:

Firefox 64 introduces an entirely new API, browser.menus.overrideContext, which allows complete customization of the context menu shown within add-on content like sidebars, popups, etc.

This is illustrated right in the post by my favorite pain point, the Tree Stye Tab custom tab menu mixing with the regular tab menu.

Finally!