* [](#)
* Firefox Source Tree Documentation
* [Report an issue](https://bugzilla.mozilla.org/enter_bug.cgi?product=Developer+Infrastructure&component=Firefox+Source+Docs%3A+Content&short_desc=Documentation+issue+on+index&comment=URL+=+https://firefox-source-docs.mozilla.org/index.html&bug_file_loc=https://firefox-source-docs.mozilla.org/index.html) / [View page source](_sources/index.rst.txt)
* * *
Firefox Source Tree Documentation[](#firefox-source-tree-documentation "Link to this heading")
===============================================================================================
Overview
* [A Glossary of Common Terms](glossary/index.html)
* [A Quick Guide to Mozilla Applications](overview/index.html)
* [Gecko](overview/gecko.html)
* [Firefox for Desktop](browser/overview.html)
* [Firefox for iOS](overview/ios.html)
Getting Started
* [Getting Set Up To Work On The Firefox Codebase](setup/index.html)
Working On Firefox
* [Working on Firefox](contributing/index.html)
* [Firefox Contributors’ Quick Reference](contributing/contribution_quickref.html)
* [Working with stack of patches Quick Reference](contributing/stack_quickref.html)
* [Pocket Guide: Shipping Firefox](contributing/pocket-guide-shipping-firefox.html)
* [Editor / IDE integration](contributing/editor.html)
* [Getting reviews](contributing/reviews.html)
* [Levelling up](contributing/levelling-up.html)
* [How to submit a patch](contributing/how_to_submit_a_patch.html)
* [Data Review](contributing/data-review.html)
* [Code Review FAQ](contributing/Code_Review_FAQ.html)
* [Reviewer Checklist](contributing/reviewer_checklist.html)
* [Mercurial Overview](contributing/vcs/mercurial.html)
* [Mercurial Bundles](contributing/vcs/mercurial_bundles.html)
* [Capturing a minidump](contributing/debugging/capturing_minidump.html)
* [Debugging A Hang On macOS](contributing/debugging/debugging_a_hang_on_macos.html)
* [Debugging A Minidump](contributing/debugging/debugging_a_minidump.html)
* [Debugging Firefox with GDB](contributing/debugging/debugging_firefox_with_gdb.html)
* [Debugging Firefox with LLDB](contributing/debugging/debugging_firefox_with_lldb.html)
* [Debugging Firefox with Pernosco](contributing/debugging/debugging_firefox_with_pernosco.html)
* [Debugging Firefox with rr](contributing/debugging/debugging_firefox_with_rr.html)
* [Debugging Firefox with Valgrind](contributing/debugging/debugging_firefox_with_valgrind.html)
* [Debugging On macOS](contributing/debugging/debugging_on_macos.html)
* [Debugging On Windows](contributing/debugging/debugging_on_windows.html)
* [Debugging WebRTC Calls](contributing/debugging/debugging_webrtc_calls.html)
* [Symbolicating TreeHerder stacks locally](contributing/debugging/local_symbols.html)
* [How to get a process dump with Windows Task Manager](contributing/debugging/process_dump_task_manager.html)
* [How to get a stacktrace for a bug report](contributing/debugging/stacktrace_report.html)
* [How to get a stacktrace with WinDbg](contributing/debugging/stacktrace_windbg.html)
* [Understanding Crash Reports](contributing/debugging/understanding_crash_reports.html)
* [Signing Local macOS Builds](contributing/signing/signing_macos_build.html)
* [Firefox Source Code Directory Structure](contributing/directory_structure.html)
* [Understanding Artifact Builds](contributing/build/artifact_builds.html)
* [Firefox for Mobile Devices](contributing/build/building_mobile_firefox.html)
* [Supported Build Hosts and Targets](contributing/build/supported.html)
* [Engineering Show and Tell](contributing/engineering_show_and_tell.html)
* [Filing good bugs](contributing/filing-good-bugs.html)
* [Bug Handling](bug-mgmt/index.html)
* [Guides](bug-mgmt/index.html#guides)
* [Policies](bug-mgmt/index.html#policies)
* [Processes](bug-mgmt/index.html#processes)
* [Related documentation](bug-mgmt/index.html#related-documentation)
Firefox User Guide
* [Firefox DevTools User Docs](devtools-user/index.html)
* [The Core Tools](devtools-user/index.html#the-core-tools)
* [More Tools](devtools-user/index.html#more-tools)
* [Connecting the Developer Tools](devtools-user/index.html#connecting-the-developer-tools)
* [Debugging the browser](devtools-user/index.html#debugging-the-browser)
* [Extending DevTools](devtools-user/index.html#extending-devtools)
* [Migrating from Firebug](devtools-user/index.html#migrating-from-firebug)
* [Contribute](devtools-user/index.html#contribute)
Source Code Documentation
* [Governance](mots/index.html)
* [Overview](mots/index.html#overview)
* [Modules](mots/index.html#modules)
* [Firefox Front-end](browser/index.html)
* [Address Bar](browser/urlbar/index.html)
* [Browser Usage Telemetry](browser/BrowserUsageTelemetry.html)
* [Frontend Code Review Best Practices](browser/FrontendCodeReviewBestPractices.html)
* [Command Line Parameters](browser/CommandLineParameters.html)
* [Browser Startup](browser/BrowserStartup.html)
* [CustomizableUI Component](browser/components/customizableui/docs/index.html)
* [Enterprise Policies](browser/components/enterprisepolicies/docs/index.html)
* [Form Autofill](browser/extensions/formautofill/docs/index.html)
* [Firefox Home (New Tab)](browser/extensions/newtab/docs/index.html)
* [Firefox Welcome Experience (about:welcome)](browser/components/aboutwelcome/docs/index.html)
* [Installer](browser/installer/windows/installer/index.html)
* [Installation Attribution](browser/components/attribution/docs/index.html)
* [Default Browser Agent](toolkit/mozapps/defaultagent/default-browser-agent/index.html)
* [Migration](browser/components/migration/docs/index.html)
* [PageDataService](browser/components/pagedata/docs/index.html)
* [Places](browser/places/index.html)
* [Messaging System](browser/components/asrouter/docs/index.html)
* [Search](browser/search/index.html)
* [tabbrowser](browser/base/tabbrowser/index.html)
* [Touch Bar](browser/touchbar/index.html)
* [UITour](browser/components/uitour/docs/index.html)
* [Firefox Branding](browser/branding/docs/index.html)
* [Storybook for Firefox](browser/components/storybook/docs/README.storybook.stories.html)
* [Reusable UI widgets](browser/components/storybook/docs/README.reusable-widgets.stories.html)
* [Other types of UI Widgets](browser/components/storybook/docs/README.other-widgets.stories.html)
* [Lit](browser/components/storybook/docs/README.lit-guide.stories.html)
* [XUL and HTML](browser/components/storybook/docs/README.xul-and-html.stories.html)
* [Design tokens](toolkit/themes/shared/design-system/docs/README.design-tokens.stories.html)
* [JSON design tokens](toolkit/themes/shared/design-system/docs/README.json-design-tokens.stories.html)
* [Backup Component](browser/components/backup/docs/index.html)
* [DOM](dom/index.html)
* [DOM IPC](dom/ipc/index.html)
* [DOM Navigation](dom/navigation/index.html)
* [Push](dom/push/index.html)
* [Script Security](dom/scriptSecurity/index.html)
* [Xray Vision](dom/scriptSecurity/xray_vision.html)
* [DOM Workers & Storage](dom/workersAndStorage/index.html)
* [Web IDL bindings](dom/webIdlBindings/index.html)
* [IOUtils Migration Guide](dom/ioutils_migration.html)
* [Federated Credential Management](dom/fedcm.html)
* [Implementing specifications using WHATWG Streams API](dom/streams.html)
* [Use Counters](dom/use-counters.html)
* [Editor](editor/index.html)
* [Editor module structure](editor/EditorModuleStructure.html)
* [Editor module specific rules](editor/EditorModuleSpecificRules.html)
* [IME handling guide](editor/IMEHandlingGuide.html)
* [Style system (CSS) & Layout](layout/index.html)
* [Style System Overview](layout/StyleSystemOverview.html)
* [Layout Overview](layout/LayoutOverview.html)
* [Dynamic change handling along the rendering pipeline](layout/DynamicChangeHandling.html)
* [Layout Engine Visual Tests (reftest)](layout/Reftest.html)
* [Layout Debugger](layout/LayoutDebugger.html)
* [AccessibleCaret](layout/AccessibleCaret.html)
* [Graphics](gfx/index.html)
* [Rendering Overview](gfx/RenderingOverview.html)
* [Layers History](gfx/LayersHistory.html)
* [Asynchronous Panning and Zooming](gfx/AsyncPanZoom.html)
* [Silk Overview](gfx/Silk.html)
* [Moz2D](gfx/Moz2D.html)
* [Processes, Threads and IPC](ipc/index.html)
* [IPDL: Inter-Thread and Inter-Process Message Passing](ipc/ipdl.html)
* [Gecko Processes](ipc/processes.html)
* [Utility Process](ipc/utility_process.html)
* [Firefox DevTools Contributor Docs](devtools/index.html)
* [Getting Started](devtools/index.html#getting-started)
* [Contributing](devtools/index.html#contributing)
* [Recurring tasks](devtools/index.html#recurring-tasks)
* [Automated tests](devtools/index.html#automated-tests)
* [Files and directories](devtools/index.html#files-and-directories)
* [Tool Architectures](devtools/index.html#tool-architectures)
* [Frontend](devtools/index.html#frontend)
* [Backend](devtools/index.html#backend)
* [Preferences](devtools/index.html#preferences)
* [Toolkit](toolkit/index.html)
* [JavaScript Logging](toolkit/javascript-logging.html)
* [Add-on Manager](toolkit/mozapps/extensions/addon-manager/index.html)
* [Background Task Mode](toolkit/components/backgroundtasks/index.html)
* [Crash Manager](toolkit/components/crashes/crash-manager/index.html)
* [Crash Reporter](toolkit/crashreporter/crashreporter/index.html)
* [Internal URLs](toolkit/internal-urls.html)
* [Search Service](toolkit/search/index.html)
* [Shield Recipe Client](toolkit/components/normandy/normandy/index.html)
* [Nimbus](toolkit/components/nimbus/docs/index.html)
* [Messaging System Schemas](toolkit/components/messaging-system/docs/index.html)
* [Picture-in-Picture](toolkit/components/pictureinpicture/pictureinpicture/index.html)
* [Prompts](toolkit/components/prompts/prompts/index.html)
* [Subprocess Module](toolkit/modules/subprocess/toolkit_modules/subprocess/index.html)
* [Telemetry](toolkit/components/telemetry/index.html)
* [Firefox on Glean (FOG)](toolkit/components/glean/index.html)
* [Toolkit Modules](toolkit/modules/toolkit_modules/index.html)
* [Toolkit Widgets](toolkit/content/toolkit_widgets/index.html)
* [Fingerprinting Resistance](toolkit/components/resistfingerprinting/resistfingerprinting/index.html)
* [URL Classifier](toolkit/components/url-classifier/url-classifier/index.html)
* [WebExtensions API Development](toolkit/components/extensions/webextensions/index.html)
* [Managing the built-in en-US dictionary](extensions/spellcheck/index.html)
* [Application Update](toolkit/mozapps/update/docs/index.html)
* [Anti-Tracking](toolkit/components/antitracking/anti-tracking/index.html)
* [Translations](toolkit/components/translations/index.html)
* [Session Store](toolkit/components/sessionstore/index.html)
* [SpiderMonkey](js/index.html)
* [Building and testing SpiderMonkey](js/build.html)
* [Running Automated JavaScript Tests](js/test.html)
* [Hacking Tips](js/hacking_tips.html)
* [Debugger API](js/Debugger/index.html)
* [SavedFrame](js/SavedFrame/index.html)
* [JavaScript Language Feature Checklist](js/feature_checklist.html)
* [So You Want to Add a Bytecode Op](js/bytecode_checklist.html)
* [Adding Use Counter Telemetry to the JS Engine](js/use_counter.html)
* [Components of SpiderMonkey](js/index.html#components-of-spidermonkey)
* [JS Loader](jsloader/index.html)
* [System Modules](jsloader/system-modules.html)
* [JS Loader APIs](jsloader/jsloader-api.html)
* [GeckoView](mobile/android/geckoview/index.html)
* [Documentation](mobile/android/geckoview/index.html#documentation)
* [More information](mobile/android/geckoview/index.html#more-information)
* [Fenix](mobile/android/fenix/index.html)
* [Acronym Dictionary](mobile/android/fenix/Acronym-dictionary.html)
* [Addressing a performance regression](mobile/android/fenix/Addressing-a-performance-regression.html)
* [Architecture Decisions](mobile/android/fenix/Architecture-Decisions.html)
* [Architecture Overview](mobile/android/fenix/architecture-overview.html)
* [Crash Monitoring](mobile/android/fenix/Crash-Monitoring.html)
* [Creating a release branch](mobile/android/fenix/Creating-a-release-branch.html)
* [Data practises](mobile/android/fenix/Data-Practices.html)
* [Development Test Plan](mobile/android/fenix/Development-Test-Plan.html)
* [Fennec Legacy: Migration](mobile/android/fenix/Fennec-Migration.html)
* [Firebase Cloud Messaging for WebPush](mobile/android/fenix/Firebase-Cloud-Messaging-for-WebPush.html)
* [Firefox for Android Team Processes](mobile/android/fenix/Firefox-for-Android-Team-Processes.html)
* [Home](mobile/android/fenix/Home.html)
* [Implementing Telemetry](mobile/android/fenix/Implementing-Telemetry.html)
* [Implementing a Nimbus Experiment](mobile/android/fenix/Implementing-a-Nimbus-Experiment.html)
* [List of Fenix Threads](mobile/android/fenix/List-of-fenix-threads.html)
* [Logging Crash Information](mobile/android/fenix/Logging-Crash-Information.html)
* [Metric Feature Tags](mobile/android/fenix/Metric-Feature-Tags.html)
* [Debug settings menu instructions](mobile/android/fenix/Secret-settings-debug-menu-instructions.html)
* [Telemetry - Implementation, Reviews, Renewals](mobile/android/fenix/Telemetry-implementation%2C-reviews%2C-renewals.html)
* [Creating Glean Annotations](mobile/android/fenix/Telemetry-implementation%2C-reviews%2C-renewals.html#creating-glean-annotations)
* [Data review](mobile/android/fenix/Telemetry-implementation%2C-reviews%2C-renewals.html#data-review)
* [Renewing existing telemetry](mobile/android/fenix/Telemetry-implementation%2C-reviews%2C-renewals.html#renewing-existing-telemetry)
* [Test Telemetry Pings](mobile/android/fenix/Test-telemetry-pings.html)
* [Working with Strings](mobile/android/fenix/Working-with-Strings.html)
* [Adjust](mobile/android/fenix/adjust.html)
* [Certificates](mobile/android/fenix/certificates.html)
* [Crash Reporting](mobile/android/fenix/crash-reporting.html)
* [Experiments](mobile/android/fenix/experiments.html)
* [Manual Testing](mobile/android/fenix/manual-testing.html)
* [Metrics Definitions](mobile/android/fenix/metrics.html)
* [Release Checklist](mobile/android/fenix/release-checklist.html)
* [Substituting Local GeckoView](mobile/android/fenix/substituting-local-gv.html)
* [Sync Integration Tests](mobile/android/fenix/syncIntegrationTests.html)
* [Telemetry](mobile/android/fenix/telemetry.html)
* [UI Tests](mobile/android/fenix/UI-Tests.html)
* [Focus for Android](mobile/android/focus-android/index.html)
* [Architecture Decisions](mobile/android/focus-android/Architecture-Decisions.html)
* [Battery Debugging](mobile/android/focus-android/Battery-Debugging.html)
* [Content blocking](mobile/android/focus-android/Content-blocking.html)
* [Crash Reporting with Sentry](mobile/android/focus-android/Crash-Reporting-with-Sentry.html)
* [Development Custom GeckoView](mobile/android/focus-android/Development-Custom-GeckoView.html)
* [Feature & Issue workflow](mobile/android/focus-android/Feature-%26-Issue-workflow.html)
* [Running GeckoView in a debug environment](mobile/android/focus-android/GeckoView-%28In-Progress%29.html)
* [Home](mobile/android/focus-android/Home.html)
* [Homescreen Tips](mobile/android/focus-android/Homescreen-Tips.html)
* [Multisession architecture](mobile/android/focus-android/Multisession-architecture.html)
* [Recommended pre-push hook](mobile/android/focus-android/Recommended-pre-push-hook.html)
* [Release Process](mobile/android/focus-android/Release-Process.html)
* [Release tracks](mobile/android/focus-android/Release-tracks.html)
* [Removing strings](mobile/android/focus-android/Removing-strings.html)
* [Sprint Process](mobile/android/focus-android/Sprint-Process.html)
* [Telemetry](mobile/android/focus-android/Telemetry.html)
* [UI Test](mobile/android/focus-android/UI-Test.html)
* [WebIDL](dom/bindings/webidl/index.html)
* [Overview](dom/bindings/webidl/index.html#overview)
* [WebIDL source file flavors](dom/bindings/webidl/index.html#webidl-source-file-flavors)
* [Producing C++ code](dom/bindings/webidl/index.html#producing-c-code)
* [Requirements](dom/bindings/webidl/index.html#requirements)
* [libpref](modules/libpref/index.html)
* [High-level design](modules/libpref/index.html#high-level-design)
* [Low-level details](modules/libpref/index.html#low-level-details)
* [Networking](networking/index.html)
* [How-to’s](networking/index.html#how-to-s)
* [Tutorials](networking/index.html#tutorials)
* [Deep Dives](networking/index.html#deep-dives)
* [References](networking/index.html#references)
* [Remote Protocols](remote/index.html)
* [Common documentation](remote/index.html#common-documentation)
* [Protocols](remote/index.html#protocols)
* [Architecture](remote/index.html#architecture)
* [Bugs](remote/index.html#bugs)
* [Communication](remote/index.html#communication)
* [Services](services/index.html)
* [Remote Settings](services/settings/index.html)
* [Sync](services/sync/index.html)
* [Permissions](permissions/index.html)
* [Permission Manager](permissions/manager.html)
* [Remote Permissions](permissions/remote.html)
* [File Handling](uriloader/index.html)
* [URI Loader Service](uriloader/uriloader.html)
* [External Helper App Service](uriloader/exthandler/index.html)
* [Firefox on macOS](widget/cocoa/index.html)
* [Using macOS APIs](widget/cocoa/macos-apis.html)
* [A primer on macOS SDKs](widget/cocoa/sdks.html)
* [Firefox on Windows](widget/windows/index.html)
* [Windows DLL Blocklisting](widget/windows/blocklist.html)
* [Windows Pointing Device Support in Firefox](widget/windows/windows-pointing-device/index.html)
* [Windows Limited Access Features](widget/windows/LimitedAccessFeature.html)
* [Firefox AI Runtime](toolkit/components/ml/index.html)
* [Architecture](toolkit/components/ml/architecture.html)
* [APIs](toolkit/components/ml/api.html)
* [Notifications](toolkit/components/ml/notifications.html)
* [Models management](toolkit/components/ml/models.html)
* [How to perftest a model](toolkit/components/ml/perf.html)
* [WebExtensions AI API](toolkit/components/ml/extensions.html)
* [Trial Inference API Extension Example](toolkit/components/ml/extensions-api-example/README.html)
* [Accessibility](accessible/index.html)
* [Architecture](accessible/Architecture.html)
* [Document Accessibility Lifecycle](accessible/DocumentAccessibilityLifecycle.html)
* [GeckoView Thread Topography](accessible/GeckoViewThreadTopography.html)
* [Colors and High Contrast Mode](accessible/ColorsAndHighContrastMode.html)
* [HCM Settings](accessible/HCMSettings.html)
* [High Contrast Mode (HCM) Media Queries](accessible/HCMMediaQueries.html)
* [Media Playback](media/index.html)
* [MediaFormatReader](media/MediaFormatReader.html)
* [Code quality](code-quality/index.html)
* [Static Analysis](code-quality/static-analysis/index.html)
* [Linting](code-quality/lint/index.html)
* [Coding style](code-quality/coding-style/index.html)
* [Writing Rust Code](writing-rust-code/index.html)
* [Basics](writing-rust-code/basics.html)
* [Rust/C++ interop](writing-rust-code/cpp-interop.html)
* [Rust Update Policy](writing-rust-code/update-policy.html)
* [XPCOM components in Rust](writing-rust-code/xpcom.html)
* [Rust Components](rust-components/index.html)
* [Topic Guides](rust-components/topic-guides/index.html)
* [API References](rust-components/api/index.html)
* [Developing Rust Components](rust-components/developing-rust-components/index.html)
* [Gecko Profiler](tools/profiler/index.html)
* [Profiler Code Overview](tools/profiler/code-overview.html)
* [Buffers and Memory Management](tools/profiler/buffer.html)
* [Instrumenting JavaScript](tools/profiler/instrumenting-javascript.html)
* [Instrumenting Rust](tools/profiler/instrumenting-rust.html)
* [Instrumenting Android](tools/profiler/instrumenting-android.html)
* [Markers](tools/profiler/markers-guide.html)
* [Profiling Memory](tools/profiler/memory.html)
* [Profiling Sandbox violations (Linux)](tools/profiler/sandbox.html)
* [Performance](performance/index.html)
* [General Performance references](performance/index.html#general-performance-references)
* [Memory profiling and leak detection tools](performance/index.html#memory-profiling-and-leak-detection-tools)
* [Profiling and performance tools](performance/index.html#profiling-and-performance-tools)
* [Power Profiling](performance/index.html#power-profiling)
* [Performance Metrics](performance/index.html#performance-metrics)
* [Database bindings (SQLite, KV, …)](storage/index.html)
* [XPCOM](xpcom/index.html)
* [Consuming XPCOM functionality](xpcom/index.html#consuming-xpcom-functionality)
* [Tooling around XPCOM](xpcom/index.html#tooling-around-xpcom)
* [Writing new XPCOM interfaces/classes](xpcom/index.html#writing-new-xpcom-interfaces-classes)
* [NSPR](nspr/index.html)
* [Documentation](nspr/index.html#documentation)
* [Getting NSPR](nspr/index.html#getting-nspr)
* [Community](nspr/index.html#community)
* [Related Topics](nspr/index.html#related-topics)
* [Network Security Services (NSS)](security/nss/index.html)
* [Web Security Checks in Gecko](content-security/index.html)
* [Key Concepts and Terminology](content-security/index.html#key-concepts-and-terminology)
* [Loading Lifecycle in Firefox](content-security/index.html#loading-lifecycle-in-firefox)
* [Security Checks During Loading](content-security/index.html#security-checks-during-loading)
The Firefox Build System
* [Mach](mach/index.html)
* [Pushing to Try](tools/try/index.html)
* [Build System](build/buildsystem/index.html)
* [Firefox CI and Taskgraph](taskcluster/index.html)
* [Managing Documentation](tools/moztreedocs/index.html)
* [Vendoring Third Party Components](mozbuild/vendor/index.html)
Testing & Test Infrastructure
* [Automated Testing](testing/automated-testing/index.html)
* [Understanding Treeherder Results](testing/treeherder-try/index.html)
* [Sheriffed intermittent failures](testing/sheriffed-intermittents/index.html)
* [Turning on Firefox tests for a new configuration](testing/tests-for-new-config/index.html)
* [Avoiding intermittent tests](testing/intermittent/index.html)
* [Testing Policy](testing/testing-policy/index.html)
* [Configuration Changes](testing/ci-configs/index.html)
* [Browser chrome mochitests](testing/browser-chrome/index.html)
* [Chrome Tests](testing/chrome-tests/index.html)
* [Marionette](testing/marionette/index.html)
* [geckodriver](testing/geckodriver/index.html)
* [Test Verification](testing/test-verification/index.html)
* [WebRender Tests](testing/webrender/index.html)
* [Mochitest](testing/mochitest-plain/index.html)
* [XPCShell tests](testing/xpcshell/index.html)
* [TPS](testing/tps/index.html)
* [web-platform-tests](web-platform/index.html)
* [GTest](gtest/index.html)
* [Fuzzing](tools/fuzzing/index.html)
* [Sanitizer](tools/sanitizer/index.html)
* [Performance Testing](testing/perfdocs/index.html)
* [Code coverage](tools/code-coverage/index.html)
* [Testing & Debugging Rust Code](testing-rust-code/index.html)
Releases & Updates
* [Mozilla Update Infrastructure](update-infrastructure/index.html)
* [Watershed Updates](update-infrastructure/index.html#watershed-updates)
* [Desupport Updates](update-infrastructure/index.html#desupport-updates)
* [Update Verify](tools/update-verify/index.html)
Localization & Internationalization
* [Internationalization](intl/index.html)
* [Locale management](intl/locale.html)
* [UI Internationalization](intl/dataintl.html)
* [ICU](intl/icu.html)
* [ICU4X](intl/icu4x.html)
* [Localization](l10n/index.html)
* [Localization](l10n/overview.html)
* [Fluent](l10n/fluent/index.html)
* [Migrating Strings From Legacy or Fluent Files](l10n/migrations/index.html)
* [Single localization source for multiple builds](l10n/singlel10nsource.html)
* [L10N Glossary](l10n/glossary.html)
Firefox and Python
* [mozbase](mozbase/index.html)
* [Using third-party Python packages](python/index.html)
Metrics Collected in Firefox
* [Metrics](metrics/index.html)
Indices and tables[](#indices-and-tables "Link to this heading")
-----------------------------------------------------------------
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