Oh god, really? :O

Checking that link ASAP!

Thank you for explanation. :D If Waterfox will be installed on my internal drive and used as main browser then I think I should use normal version instead of portable one, am I right?

What version do you use?

What browser do you use? I think this link does not contain all extensions - Waterfox's developer said that he archived these (they will be added to next Waterfox release) and it's 60+ GB. That link has not that much data. :D

TL;DR of responses I've got so far:

- There is no still Mozilla supported version of Firefox with legacy extensions support.
- There are some forks of Firefox which still support legacy extensions (like Waterfox and Pale Moon) I should try.
- Mozilla is going to remove legacy Firefox extensions from their portal for extensions in early October.

Yeah, I noticed. :\
I'm using FF 52 ESR x64.
Isn't there any way to obtain those .xpi files for other addons?
I don't know what to do with the sources from Github..

I think Mozilla hasn't deleted them *yet*. What addons are you looking for, any example?

Well lol, all of them. This is my full list:
- Automatic Save Folder 1.0.5b129
- BarTab Lite X 1.8
- Blur 7.8.2431
- CacheViewer 0.8.6.3.1-let-fixed
- Classic Theme Restorer 1.7.7.2
- Classic Toolbar Buttons 1.6.1
- Cookie AutoDelete 1.4.4
- DownThemAll! 3.0.8
- Extension List Dumper 2 1.0.2
- Google Search "View Image" Button 1.5
- Hide Unwanted Results of Google Search 1.6
- History Cleaner 1.2.2
- Keepa - Amazon Price Tracker 3.29
- NoScript 5.1.8.4
- Open With 6.8.6
- Search by Image 1.18.0
- Session Manager 0.8.1.13
- Tab Groups 2.1.4
- Tab Groups Helper 1.0.30
- Tab Mix Plus 0.5.0.4
- uBlock Origin 1.17.0
- Video DownloadHelper 6.3.3
- Windows Favorites 1.0.4
- YouTube Plus 1.9.6

Have you checked them on Mozilla site?

For example https://addons.mozilla.org/en-US/firefox/addon/downthemall/ is still available so I think the rest should be also.

If the current extension version compatible with legacy FF is not on site then download the latest available legacy version and it should update in Firefox if the author submitted it to Mozilla (according to article I linked earlier) or you could look for it on extension homepage.

51, since after that, it starts breaking my addons.

I haven't experienced any major instabilities with Firefox Quantum myself yet, just loss of functionality of a handful of extensions. Some of which I can live without for now and others which are more painful to live without.

Over the years I have tried out a fair variety of Firefox forks, not as an alternative to Firefox but just to try them out to see what they had to offer, both in Linux and in Windows platforms. Ultimately I never found any of them offered anything major compared to using Firefox itself plus addons. Also, being forks of Firefox they are all inherently reliant on Mozilla's own codebase in order for them to move forward, so they are all Firefox from yesterday so to speak in that they're always going to be merging in new code from Mozilla but delayed by some amount of time, and making it work with whatever their own code changes are. Mozilla is a huge organization however, and most if not all of the forks out there are of small groups of people that don't have a fraction of the developer or financial resources that Mozilla has, and since their codebase is dependent on Mozilla's for forward movement, I'd rather stick with the horse's mouth that gets more usage in the real world and rapid security/bugfix updates than with any spinoffs that have development resource contraints on such a large code base.

In the majority of cases where I've had problems with Firefox for the last decade plus, most of them can be tracked down to problems caused by poorly written browser addons and not really the cause or fault of the actual browser itself. That includes but is not limited to memory leaks and other resource usage/bloat, instability, and other factors.

I might try out other browsers for the heck of it just to see what they offer as people often ask me about such things, but realistically I can't see myself shifting away from Firefox as my primary browser. Any shift to another browser to get away from any disappointments in Firefox, would result in taking on a much larger set of disappointments and limitations in any other browser alternative that exist which I might consider. In other words, even with any weaknesses Firefox might have at a given point in time, it's still the best browser option available for my needs and it has a huge team of people working on it so it has the largest likelihood of eventually fixing any problems I encounter with it over time, or having addons developed for it that work around them.

Aside from that, I use Chrome occasionally as a backup if I have a problem with a given page or whatnot and that usually suffices.

If push came to shove though, I'd rather fire up gdb and debug a problem in Firefox, fix it and patch the code myself than switch to some other random browser, it'd be less painful for me personally.

I don't think that Mozilla already removed the legacy ones, I can still see the pages of abandoned ones.
I guess all those marked with "Not compatible with Firefox Quantum" are going to be killed?

Oh, so even legacy addons weren't "so compatible" - I'm lucky I haven't used such extensions.

So this should be your primary source to get backup.

Yes, according to the article I've found. :(
(and that probably includes legacy versions of these currently Quantum-compatible as well)

But I haven't understood how.
I only see "Add to Firefox" not "Download" or something.
And those addons hosted on Github only offer the source.

Well, I do not use big number of addons, just a few, so losing even one of them is not good for me as they are integral part of my browsing experience.

At this stage, I treat Quantum as whole new browser (because it does not have options I used to have for years) so Firefox legacy forks aren't just "Firefox itself plus addons" for me - they are rather "back to roots after some expedition to unknown land". :D

Yes, I will probably go back to Quantum at some point (as it is a cost of progress in digital world) but I hope Quantum (at that time in future) will improve and have all options I (and the extensions' developers) need. I hoped this progress would be faster but when after a year Mozilla still hasn't allowed Quantum to implement Tab Mix Plus, one of my top extensions, then "something is wrong here".

I have no such knowledge. :D

RMB on "Add to Firefox" and then "Save Link As...".

I guess? If there are no performance differences between the two versions and the portable version can update as easy as the installer version, it all falls down on how you wish to manage that installation. When I reinstall Windows, or wish to bring my profile to another computer, I move my /AppData/ stuff. If you don't want to deal with that and keep things more accessible then using the portable version would make sense.

Not knowing how all of this applies makes it hard to recommend one or another, so I would say unless you need it to be portable at some point in time, I would assume using the standard version to be better? It's up to you.

EDIT: Switched up a sentence.

Oh lol, I didn't know I could do that for addons. Thank you!

EDIT: all saved! :D