Martin Brinkmann reports via gHacks:
Mozilla announced a couple of days ago that it plans to make Firefox support only WebExtensions add-ons by the end of 2017.
While that seems far far away right now, it is almost certain that things won't be ready by then. What I mean by that is that WebExtensions capabilities won't match those of Firefox's current system. While popular add-ons like NoScript will likely be ported over thanks to Mozilla working with developers actively on implementing missing API features, the same cannot be said for other add-ons.
[...] A recent post by Aris, developer of Classic Theme Restorer (CTR) and several other popular add-ons such as Classic Toolbar Buttons, NewScrollbars, or GlassMyFox, suggests that Classic Theme Restorer may be dead by the end of 2017. While Aris seems to have interest in porting over his extensions to WebExtensions, he notes that this is not possible right now.
Now [it's] real. CTR as we know it (and all my other Firefox add-ons), will be discontinued by the end of 2017. We still have no way to change [the] Firefox UI using WebExtensions and all my add-ons are about UI modifications. Seems like [it's] almost time to get used to another browser.
The end of the popular browser extension would bring the Australis design of Firefox to all users who relied on Classic Theme Restorer up until that point.
This highlights one of the main concerns that the move to WebExtensions exclusivity raises: The APIs are not there yet. In fact, a whole category of add-ons--all that modify the browser UI--cannot be ported over because of missing APIs and the situation may be similar in other areas. What makes this even more problematic than it is is that [...] no one seems to know whether the capabilities that WebExtensions APIs will deliver, once they are made available, will be sufficient to port add-ons over.
[...] Mozilla could have waited with the move until APIs are ready for the most part, but the organization decided not to do so.
(Score: 4, Informative) by Anonymous Coward on Monday November 28 2016, @08:10PM
Main features (on CTRs preferences window)
Tab appearance: squared tabs (classic)
Tab appearance: curved tabs (all colored and visible)
Tabs not on top + [tabsontop="false/true"] attribute
Tab width and height settings
Tab title in Firefox titlebar
Tab loading animations
Tab close button on all tabs, active tab, toolbars start/end
Restore tabs empty favicon
Custom 'new tab' page url (Firefox 41+)
Double click on tabs toolbar opens 'new' tab [Windows only]
Hide tabs toolbar with one visible tab
Custom colors for tab backgrounds, text and text shadow
Custom tab separators
Application button on toolbars (+ icon variations)
Application button on titlebar [Windows only]
Custom title for application button on titlebar [Windows only]
Predefined/custom application button colors
Small navigation toolbar buttons
Movable back-forward buttons
Alternative appearance for preferences/options page
Open preferences/options page in a window (simulates preference window)
Alternative add-ons manager appearance (Firefox 40+)
Show add-ons version number inside add-ons manager (Firefox 40+)
Activity indicator (throbber) on toolbars
Bookmarks-star button in location bar
Rss-Feed button in location bar
Old Search UI (Firefox 43+)
Movable status-bar panel
Old location bar appearance (Firefox 48+)
Additional location bar
Combine stop & reload buttons
Hide location bars stop, reload & go buttons
Hide private browsing mask
Findbar on top or bottom
'Icons & Text' and 'Text only' modes
Add [iconsize="large"]/[iconsize="small"] attributes to #nav-bar node
Compact panel menus (bookmarks, history...)
Green/blue site identity button for verified websites and secure connections
Replace context menu icons with labels (Back, Forward...)
Add up to 20 additional toolbars to to top browsers area
Replace generic favicon with different icons
Favicon of a website in locations bars identity button
Different padlock icons for secure connections
AeroBlue toolbar colors for Windows 8/XP/Classic, Linux, MacOSX
Hide navigation toolbar
Inverted/white toolbar button icons
Predefined toolbar settings to alter colors, sizes, borders
Disable some of browsers default ui animations
Force some hidden toolbars to appear in fullscreen mode
Remove title/menu/tabs toolbars background color (Windows 10)
Disable browsers Loop (chat), Reader & Pocket features
...and more
https://addons.mozilla.org/en-US/firefox/addon/classicthemerestorer/ [mozilla.org]