PRELIMINARY INFO FOR VERSIONS 46 TO 52:
52-ESR
NPAPI plugins remain enabled in 32 bit version
The 64bit version supports only two NPAPI plugins: Flash and Silverlight.
disable plugins except flash: plugin.load_flash_only = false
service workers are disabled
enable: dom.serviceWorkers.enabled = true & dom.serviceWorkers.openWindow.enabled = true
push notifications are disabled
enable: enable service workers and set dom.push.enabled = true
WebAssembly (wasm) is disabled
enable: javascript.options.wasm = true
less use of multicrozess architecture Electrolysis (e10s)
uses the stricter rules of Firefox 50 for enabling it.
52
compatibility: disable all plugins except Flash
compatibility: Google Hangouts temporarily won't work
compatibility: forbids insecure HTTP sites from setting cookies with the "secure" attribute
UI: shows more warnings when login page is not https
howto disable: security.insecure_field_warning.contextual.enabled = false
feature: WebAssembly
Users of XP and Vista get migrated to 52-ESR.
51
UI change: shows warning when login page is not https
security: Firefox will save passwords even in forms that do not have “submit” events
50.0.2
50.0.1
50
UI change: "The link to check for plugin security updates has been removed from the
addon manager as Firefox automatically checks for plugin updates"
(hmm, this means that plugin updates cannot be disabled?)
49.0.2
compatibility: asynchronous rendering of the Flash plugins
49.0.1
49
compatibility: MacOS 10.6, 10.7 and 10.8 not supported any more.
compatibility: windows version requires CPU with SSE2.
compatibility: Block some nonessential Flash plugin content
DRM-blob: "Support of Widevine CDM through the EME API under GNU/Linux"
48.0.2
48.0.1
48
compatibility: add-ons must be signed by Mozilla
https://support.mozilla.org/kb/add-on-signing-in-firefox
compatibility: enables process separation (e10s) for some users
compatibility: enhanced protection from malicious downloads
https://blog.mozilla.org/security/2016/08/01/enhancing-download-protection-in-firefox/
removed Firefox Hello
47.0.2
47.0.1
47
feature: Google’s Widevine CDM on Windows and Mac OS X
video streaming services can switch from Silverlight to encrypted HTML5 video
feature: VP9 video codec
feature: embedded YouTube videos now play with HTML5 video if Flash is not installed
compatibility: removed click-to-activate plugin whitelist
compatibility: removed FUEL (Firefox User Extension Library for add-ons)
compatibility: "some Changes that can affect add-on compatibility"
https://blog.mozilla.org/addons/2016/04/07/compatibility-for-firefox-47/
46.0.1
46
compatibility: GTK3 integration (GNU/Linux only)
phone home: if you enter a one-word URL, Firefox will do a web search, instead of going to that server. You can whitelist URLs by creating a boolean pref with name "browser.fixup.domainwhitelist.",
followed by the word to be whitelisted.
More info: "snappier searches".
phone home: search suggestions on the Firefox Start (about:home) and new tab (about:newtab) pages.
feature: video-format H.264 using a binary plugin from Cisco (running in a sandbox). to disable it: set media.gmp-gmpopenh264.enabled to false,
to remove it: set media.gmp-gmpopenh264.provider.enabled to false.
lots of bloat, for example cubic-bezier curves editor (only for developers).
Version 32
phone home: malware download detection (see v31) now sends file-info to Google.
new cache
leaves old cache data on disk, and makes its own read-ahead.
password manager stores historical use information (why?).
security enhancement:
public key pinning
(static list of CAs responsible for some selected sites).
compatibility: the installer deletes the directory 'distribution'.
compatibility: preferences capability.policy.* removed (except checkloaduri for file:// URIs).
security: detect malware downloads
with local white & blacklist.
Can be disabled by settting browser.safebrowsing.appRepURL to empty string,
or by disabling the whole safebrowsing feature.
Plugins
needwhitelisting,
otherwise they are blocked (click-to-play).
Flash is not on the whitelist.
This does not affect plugins that are part of an extension.
UI: sidebars button "enables faster access to social, bookmark, & history sidebars".
compatibility: outdated and insecure NTLM-authentication deactivated.
compatibility: breaks Citrix Receiver.
Version 29
new sync for bookmarks, history, passwords, open tabs.
Incompatible with old sync, no migration available so far, requires new Firefox account, different setup method. If you had disabled sync by hiding its setup,
this change probably makes it reachable again.
The Firefox menu on the left was replaced with a rectangle full of tiles on the right.
The big orange menu button in the upper left corner was replaced with a
small line-triplett
on the right side of the address bar. The original main menu from the time before the orange button
can still be re-enabled (F10, View, Toolbars, Menu Bar), and the triple-line thingy
can be removed with "#PanelUI-button {display:none !important}" in userChrome.css.
The what's new
page for this version (shown on the first run) contains a slideshow (only if viewed with Firefox 29),
which explains the new UI, highlights the new "menu"-"button", and shows the tiles. Even if you usually have the "what's new" page disabled, for this version it probably
is important to let it show up. The relevant pref is "browser.startup.homepage_override.mstone".
The add-on bar was removed, its contents were moved to the navigation bar. Some addons do not like this, need an update.
This sounds like trying to salvage the UI of the abandoned Metro-app, by implanting it into the desktop version.
The addon ClassicThemeRestorer
can undo many Australis-changes.
Pale Moon is a free clone of Firefox that will keep the
standard user interface.
supports videocodec VP9 and audiocodec Opus for WebM videos.
removed support for spdy/2.
Version 27
better encryption: enabled TLS 1.1
and TLS 1.2 by default. If some web pages stop working, change "security.tls.version.max" temporarily back from 3 to 1.
optional faster transfer protocol: added support for
SPDY 3.1.
Version 26
Java: ClickToPlay (to be extended to all plugins, except latest flash) workaround: java whitelist deployment.
Update-Service fixed: Silent automatic updates now work, even if users have no write permission. If you do not want auto-updates: double-check that "app.update.enabled" is locked to false.
Version 25
Feature 'welcome back' offers to erase the profile if it is older than 60 days. The most important part of every automatic function is the switch to turn it off:
lockPref("browser.disableResetPrompt", true);
UI: several options removed (javascript, load images, always show tab bar)
UI: logo updated
Version 22
Feature: WebRTC enables voice chat and telephone calls inside the browser.
Privacy: and it allows to find your real IP address, even if you go through a VPN. disable: media.peerconnection.enabled = false
Feature: connect speculatively to the server, before you actually click on a link
(more info)
Privacy: and it allows to spy on you, for example spammers can verify your email address
(explanation)
disable: network.http.speculative-parallel-limit = 0
(source)
Version 21
Config Compatibility: again
majorchanges
in directory structure. The file 'override.ini' and the directories 'defaults/preferences', 'defaults/profile',
'extensions', 'plugins', and 'searchplugins' have been moved to a newly created subdirectory 'browser'.
The function of the directory 'plugin'
can be restored
by setting the pref 'plugins.load_appdir_plugins' to true.
It is still possible to set the AutoConfig-prefs 'general.config.filename' and '.obscure_value' in 'defaults/pref'.
UI: Download does not open new window, flashes green arrow
Feature: can access camera and microphone
Feature: Private Browsing now per-window
Version 19
Feature: PDF-viewer built in You can disable this by setting the pref pdfjs.disabled to true
ESR 17
Version 14
Config Compatibility: directory structure changed, ignores your preference settings. Some config files from defaults/pref must be moved to defaults/preferences
to be effective. That new directory does not exist, you must create it.
It is still possible to set the Autoconfig-prefs 'general.config.filename' and '.obscure_value'
in a file in defaults/pref. By the way its filename should start with letter a, for example 'autoconfig.js'.
Feature: reset profile. Can be triggered from about:support, and from the
safe mode dialog (automatically triggered after consecutive startup crashes). Do not deploy Firefox profiles by putting them into
default user profile, and do not use add-user scripts to modify them.
Mozilla recommends to use the directory 'browser/defaults',
or the autoconfig feature. Settings made there will survive the reset.