Firefox

Links

• Homepage is https://www.mozilla.org/en-US/firefox/
• Searchfox lets you search Firefox source code
  Searchfox (mozilla central) Search
• Bugzilla is where bugs/features are tracked.
  
  Bugzilla quicksearch Search
• Firefox Source Docs documents different components of Firefox, from a developer perspective
• Firefox release notes for developers - Fun to read to find new/interesting web features

User styles

User styles let you apply your own CSS to webpages (either specific sites or the whole web).

Steps:

• In about:config set toolkit.legacyUserProfileCustomizations.stylesheets to true.
• Find or create the file ~/.mozilla/firefox/xxxxx.yourprofile/chrome/userContent.css (you may need to create the chrome directory).
• You may need to restart Firefox if you’re newly creating this file.

Wikipedia MathML

(Maybe I should move this in a separate “Wikipedia” page)

I like copying math in Wikipedia to make Anki flashcards. But rather than clicking the “edit” button, finding the LaTeX, and copying that, I’d like to display the LaTeX directly. Wikipedia has a page on how to display formulas which links to the CSS from the NativeML extension, which I’ve modified here (and kept under the same MPL license).

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

@namespace math url(http://www.w3.org/1998/Math/MathML);

@-moz-document domain(en.wikipedia.org) {
	/* ---------- Copied from https://github.com/fred-wang/webextension-native-mathml/blob/master/content-scripts/mediawiki.css ---------- */
	/* Reset some CSS properties set by MediaWiki and hide the image fallback */
	.mwe-math-mathml-a11y {
		clip: auto !important;
		overflow: visible !important;
		position: static !important;
		width: auto !important;
		height: auto !important;
		opacity: 1 !important;
		display: inherit !important;
	}
	body.mediawiki .ve-ce-mwLatexNode .mwe-math-mathml-a11y {
		/* override https://phabricator.wikimedia.org/diffusion/EMAT/browse/master/modules/ve-math/ve.ce.MWLatexNode.css */
		display: inherit !important;
	}
	/* Support where MediaWiki lazy loaded images */
	.mwe-math-mathml-inline ~ .lazy-image-placeholder,
	.mwe-math-mathml-display ~ .lazy-image-placeholder,
	/* Support where MediaWiki doesn't lazy load images */
	.mwe-math-mathml-inline + .mwe-math-fallback-image-inline,
	.mwe-math-mathml-display + .mwe-math-fallback-image-display {
		display: none !important;
	}
	/* ---------- End copied ---------- */

	*:is(:hover,:focus) > math|annotation {
		display: block;
		user-select: all;
		border: 1px solid lightblue;
		font-size: 0.5rem;
		font-family: monospace, monospace;
		position: absolute;
		top: 0px;
		left: 0px;
	}
}

/* Local Variables: */
/* tab-width: 4 */
/* css-indent-offset: 4 */
/* indent-tabs-mode: t */
/* End: */

Special URLs

Disabling Javascipt after page loaded

javascript - Is it possible to kill all scripts on a webpage after loading the page in Firefox? - Super User

Go to the browser console which is Ctrl+Shift+J. I noticed that there was no place to actually enter in JavaScript.

Set devtools.chrome.enabled to true in about:config. Then you do get a JavaScript command line.

At the JavaScript command line, enter gBrowser.selectedBrowser.browsingContext.allowJavascript = false

Android

See also /firefox-android.

You can install Firefox Nightly using an APK from https://ftp.mozilla.org/pub/fenix/. There’s also an app called FFUpdater (on F-Droid) that’ll download the latest one automatically.

Extension/add-on shortcuts/hotkeys

To manage the hotkeys for add-ons, or shortcuts for extensions, go to about:addons and then click on the settings gear and click “Manage Extension Shortcuts”.

For example, for uBlock Origin I set hotkeys for element picker, element zapper. This is also where you’d go to change the hotkeys for Firefox Multi-Account Containers.

Extra reasons I like Firefox

Or rather, some things Firefox is somewhat better at than other user agents.

• The biggest reason for me is that it’s free software or actually “open source”. While Google Chrome, Apple Safari, and Microsoft Edge use open source components, they are include proprietary components and have unfree licenses. Chromium is open source, but Chrome isn’t. WebKit is open source, but Safari isn’t.
• Scripting support in SVG. Strangely, only Firefox seems to support ECMAScript Modules within SVG documents. See https://developer.mozilla.org/en-US/docs/Web/SVG/Element/script.
• Containers/contextual identities.

  I should document Firefox Multi-Account Containers, but until I do I’ll just mention that Firefox web extensions can take advantage of containers. See https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/contextualIdentities.

• Supports ECMAScript modules in XML-serialized HTML documents (i.e. <script type="module"/> in application/xhtml+xml). Chromium can’t handle it unless it also has the async attribute. Safari/WebKit just can’t handle it at all, and don’t correctly fall back to loading “nomodule”.
• Supports extensions both on desktop and mobile. Chrome doesn’t seem to support extensions on mobile.

Things I haven’t figured out

• Getting SpeechSynthesis API to work in Linux or NixOS specifically. I think it has something to do with speech-dispatcher. Never mind. It looks like this is now working with NixOS 23.11; Firefox is compiled with speech-dispatcher support. You can then use spd-conf from speech-dispatcher to configure with TTS backend is used. Espeak has a ton of different voices.