BranchesTags

Repository files navigation

DescriptionThunderbird is a powerful and customizable open source Email client with millions of users. It is based on the Mozilla platform that Firefox is also built on. These docs teach you how to contribute!

About Thunderbird

I Want to Start Hacking

This page has some information on where to get information and how to get plugged into the Community. If you are ready to start hacking, head over to one of the following sections.

Contributing to Thunderbird

Get all the information you need to set up your development environment and get ready to hack on Thunderbird.

{% page-ref page="thunderbird-development/getting-started.md" %}

Add-on Development

If you'd like to learn to develop add-ons for Thunderbird, check out our add-on documentation with examples, tips and links to relevant resources.

{% page-ref page="add-ons/about-add-ons.md" %}

Report Bugs and Request Features

Bugzilla

Thunderbird uses Mozilla's Bugzilla platform to report and track bugs. The site can also be used to generate enhancement bugs, which can be used for feature requests. If you want to become a contributor to Thunderbird, you will need an account on Bugzilla as you will submit patches through this platform.

Profiling Thunderbird Performance

Creating a performance profile can be useful for developers to find the causes of high CPU load or slowness in Thunderbird.

Thundernest on GitHub

If you want to contribute to the Thunderbird website, this documentation, or addons.thunderbird.net - you can find those repositories and their issue trackers on the Thundernest GitHub page. You'll need a GitHub account to contribute there.

Getting Plugged into the Community

We have a complete listing of the ways in which you can get involved with Thunderbird on our website. Below are some quick references from that page that you can use if you are looking to contribute to Thunderbird core right away.

Mailing Lists

If you want to participate in discussions about Thunderbird development, these are the main channels.

  1. TB-Planning: This mailing list is higher level topics like: the future of Thunderbird, potential features, and changes that you would like to see happen. It is also used to discuss a variety of broader issues around community and governance of the project.
  2. Topicbox: A moderated mailing list for discussing engineering plans for Thunderbird. It is a place where you can raise questions and ideas for core Thunderbird development.
  3. Add-on Developers: A list for Thunderbird add-on developers and aspiring add-on developers to ask questions and share knowledge.

Chat

If you want to ask questions in real-time about how to hack on Thunderbird, you can join our development chat channel at #maildev:mozilla.org

About

Developer documentation for Thunderbird contributors.

developer.thunderbird.net

Resources

Readme
Activity

Stars

0 stars

Watchers

0 watching

Forks

0 forks
Report repository

Releases

Packages

Contributors

, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
 blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

Skip to content
BranchesTags
Repository files navigation
DescriptionThunderbird is a powerful and customizable open source Email client with millions of users. It is based on the Mozilla platform that Firefox is also built on. These docs teach you how to contribute!
About Thunderbird
I Want to Start Hacking
This page has some information on where to get information and how to get plugged into the Community. If you are ready to start hacking, head over to one of the following sections.
Contributing to Thunderbird
Get all the information you need to set up your development environment and get ready to hack on Thunderbird.
{% page-ref page="thunderbird-development/getting-started.md" %}
Add-on Development
If you'd like to learn to develop add-ons for Thunderbird, check out our add-on documentation with examples, tips and links to relevant resources.
{% page-ref page="add-ons/about-add-ons.md" %}
Report Bugs and Request Features
Bugzilla
Thunderbird uses Mozilla's Bugzilla platform to report and track bugs. The site can also be used to generate enhancement bugs, which can be used for feature requests. If you want to become a contributor to Thunderbird, you will need an account on Bugzilla as you will submit patches through this platform.
Profiling Thunderbird Performance
Creating a performance profile can be useful for developers to find the causes of high CPU load or slowness in Thunderbird.
Thundernest on GitHub
If you want to contribute to the Thunderbird website, this documentation, or addons.thunderbird.net - you can find those repositories and their issue trackers on the Thundernest GitHub page. You'll need a GitHub account to contribute there.
Getting Plugged into the Community
We have a complete listing of the ways in which you can get involved with Thunderbird on our website. Below are some quick references from that page that you can use if you are looking to contribute to Thunderbird core right away.
Mailing Lists
If you want to participate in discussions about Thunderbird development, these are the main channels.
  1. TB-Planning: This mailing list is higher level topics like: the future of Thunderbird, potential features, and changes that you would like to see happen. It is also used to discuss a variety of broader issues around community and governance of the project.
  2. Topicbox: A moderated mailing list for discussing engineering plans for Thunderbird. It is a place where you can raise questions and ideas for core Thunderbird development.
  3. Add-on Developers: A list for Thunderbird add-on developers and aspiring add-on developers to ask questions and share knowledge.
Chat
If you want to ask questions in real-time about how to hack on Thunderbird, you can join our development chat channel at #maildev:mozilla.org
About
Developer documentation for Thunderbird contributors.
developer.thunderbird.net
Resources
Readme
Activity
Stars
0 stars
Watchers
0 watching
Forks
0 forks
Report repository
Releases
Packages
Contributors

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
BranchesTags
Repository files navigation
DescriptionThunderbird is a powerful and customizable open source Email client with millions of users. It is based on the Mozilla platform that Firefox is also built on. These docs teach you how to contribute!
About Thunderbird
I Want to Start Hacking
This page has some information on where to get information and how to get plugged into the Community. If you are ready to start hacking, head over to one of the following sections.
Contributing to Thunderbird
Get all the information you need to set up your development environment and get ready to hack on Thunderbird.
{% page-ref page="thunderbird-development/getting-started.md" %}
Add-on Development
If you'd like to learn to develop add-ons for Thunderbird, check out our add-on documentation with examples, tips and links to relevant resources.
{% page-ref page="add-ons/about-add-ons.md" %}
Report Bugs and Request Features
Bugzilla
Thunderbird uses Mozilla's Bugzilla platform to report and track bugs. The site can also be used to generate enhancement bugs, which can be used for feature requests. If you want to become a contributor to Thunderbird, you will need an account on Bugzilla as you will submit patches through this platform.
Profiling Thunderbird Performance
Creating a performance profile can be useful for developers to find the causes of high CPU load or slowness in Thunderbird.
Thundernest on GitHub
If you want to contribute to the Thunderbird website, this documentation, or addons.thunderbird.net - you can find those repositories and their issue trackers on the Thundernest GitHub page. You'll need a GitHub account to contribute there.
Getting Plugged into the Community
We have a complete listing of the ways in which you can get involved with Thunderbird on our website. Below are some quick references from that page that you can use if you are looking to contribute to Thunderbird core right away.
Mailing Lists
If you want to participate in discussions about Thunderbird development, these are the main channels.
  1. TB-Planning: This mailing list is higher level topics like: the future of Thunderbird, potential features, and changes that you would like to see happen. It is also used to discuss a variety of broader issues around community and governance of the project.
  2. Topicbox: A moderated mailing list for discussing engineering plans for Thunderbird. It is a place where you can raise questions and ideas for core Thunderbird development.
  3. Add-on Developers: A list for Thunderbird add-on developers and aspiring add-on developers to ask questions and share knowledge.
Chat
If you want to ask questions in real-time about how to hack on Thunderbird, you can join our development chat channel at #maildev:mozilla.org
About
Developer documentation for Thunderbird contributors.
developer.thunderbird.net
Resources
Readme
Activity
Stars
0 stars
Watchers
0 watching
Forks
0 forks
Report repository
Releases
Packages
Contributors

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
BranchesTags
Repository files navigation
DescriptionThunderbird is a powerful and customizable open source Email client with millions of users. It is based on the Mozilla platform that Firefox is also built on. These docs teach you how to contribute!
About Thunderbird
I Want to Start Hacking
This page has some information on where to get information and how to get plugged into the Community. If you are ready to start hacking, head over to one of the following sections.
Contributing to Thunderbird
Get all the information you need to set up your development environment and get ready to hack on Thunderbird.
{% page-ref page="thunderbird-development/getting-started.md" %}
Add-on Development
If you'd like to learn to develop add-ons for Thunderbird, check out our add-on documentation with examples, tips and links to relevant resources.
{% page-ref page="add-ons/about-add-ons.md" %}
Report Bugs and Request Features
Bugzilla
Thunderbird uses Mozilla's Bugzilla platform to report and track bugs. The site can also be used to generate enhancement bugs, which can be used for feature requests. If you want to become a contributor to Thunderbird, you will need an account on Bugzilla as you will submit patches through this platform.
Profiling Thunderbird Performance
Creating a performance profile can be useful for developers to find the causes of high CPU load or slowness in Thunderbird.
Thundernest on GitHub
If you want to contribute to the Thunderbird website, this documentation, or addons.thunderbird.net - you can find those repositories and their issue trackers on the Thundernest GitHub page. You'll need a GitHub account to contribute there.
Getting Plugged into the Community
We have a complete listing of the ways in which you can get involved with Thunderbird on our website. Below are some quick references from that page that you can use if you are looking to contribute to Thunderbird core right away.
Mailing Lists
If you want to participate in discussions about Thunderbird development, these are the main channels.
  1. TB-Planning: This mailing list is higher level topics like: the future of Thunderbird, potential features, and changes that you would like to see happen. It is also used to discuss a variety of broader issues around community and governance of the project.
  2. Topicbox: A moderated mailing list for discussing engineering plans for Thunderbird. It is a place where you can raise questions and ideas for core Thunderbird development.
  3. Add-on Developers: A list for Thunderbird add-on developers and aspiring add-on developers to ask questions and share knowledge.
Chat
If you want to ask questions in real-time about how to hack on Thunderbird, you can join our development chat channel at #maildev:mozilla.org
About
Developer documentation for Thunderbird contributors.
developer.thunderbird.net
Resources
Readme
Activity
Stars
0 stars
Watchers
0 watching
Forks
0 forks
Report repository
Releases
Packages
Contributors

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

Skip to content
BranchesTags
Repository files navigation
DescriptionThunderbird is a powerful and customizable open source Email client with millions of users. It is based on the Mozilla platform that Firefox is also built on. These docs teach you how to contribute!
About Thunderbird
I Want to Start Hacking
This page has some information on where to get information and how to get plugged into the Community. If you are ready to start hacking, head over to one of the following sections.
Contributing to Thunderbird
Get all the information you need to set up your development environment and get ready to hack on Thunderbird.
{% page-ref page="thunderbird-development/getting-started.md" %}
Add-on Development
If you'd like to learn to develop add-ons for Thunderbird, check out our add-on documentation with examples, tips and links to relevant resources.
{% page-ref page="add-ons/about-add-ons.md" %}
Report Bugs and Request Features
Bugzilla
Thunderbird uses Mozilla's Bugzilla platform to report and track bugs. The site can also be used to generate enhancement bugs, which can be used for feature requests. If you want to become a contributor to Thunderbird, you will need an account on Bugzilla as you will submit patches through this platform.
Profiling Thunderbird Performance
Creating a performance profile can be useful for developers to find the causes of high CPU load or slowness in Thunderbird.
Thundernest on GitHub
If you want to contribute to the Thunderbird website, this documentation, or addons.thunderbird.net - you can find those repositories and their issue trackers on the Thundernest GitHub page. You'll need a GitHub account to contribute there.
Getting Plugged into the Community
We have a complete listing of the ways in which you can get involved with Thunderbird on our website. Below are some quick references from that page that you can use if you are looking to contribute to Thunderbird core right away.
Mailing Lists
If you want to participate in discussions about Thunderbird development, these are the main channels.
  1. TB-Planning: This mailing list is higher level topics like: the future of Thunderbird, potential features, and changes that you would like to see happen. It is also used to discuss a variety of broader issues around community and governance of the project.
  2. Topicbox: A moderated mailing list for discussing engineering plans for Thunderbird. It is a place where you can raise questions and ideas for core Thunderbird development.
  3. Add-on Developers: A list for Thunderbird add-on developers and aspiring add-on developers to ask questions and share knowledge.
Chat
If you want to ask questions in real-time about how to hack on Thunderbird, you can join our development chat channel at #maildev:mozilla.org
About
Developer documentation for Thunderbird contributors.
developer.thunderbird.net
Resources
Readme
Activity
Stars
0 stars
Watchers
0 watching
Forks
0 forks
Report repository
Releases
Packages
Contributors

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
BranchesTags
Repository files navigation
DescriptionThunderbird is a powerful and customizable open source Email client with millions of users. It is based on the Mozilla platform that Firefox is also built on. These docs teach you how to contribute!
About Thunderbird
I Want to Start Hacking
This page has some information on where to get information and how to get plugged into the Community. If you are ready to start hacking, head over to one of the following sections.
Contributing to Thunderbird
Get all the information you need to set up your development environment and get ready to hack on Thunderbird.
{% page-ref page="thunderbird-development/getting-started.md" %}
Add-on Development
If you'd like to learn to develop add-ons for Thunderbird, check out our add-on documentation with examples, tips and links to relevant resources.
{% page-ref page="add-ons/about-add-ons.md" %}
Report Bugs and Request Features
Bugzilla
Thunderbird uses Mozilla's Bugzilla platform to report and track bugs. The site can also be used to generate enhancement bugs, which can be used for feature requests. If you want to become a contributor to Thunderbird, you will need an account on Bugzilla as you will submit patches through this platform.
Profiling Thunderbird Performance
Creating a performance profile can be useful for developers to find the causes of high CPU load or slowness in Thunderbird.
Thundernest on GitHub
If you want to contribute to the Thunderbird website, this documentation, or addons.thunderbird.net - you can find those repositories and their issue trackers on the Thundernest GitHub page. You'll need a GitHub account to contribute there.
Getting Plugged into the Community
We have a complete listing of the ways in which you can get involved with Thunderbird on our website. Below are some quick references from that page that you can use if you are looking to contribute to Thunderbird core right away.
Mailing Lists
If you want to participate in discussions about Thunderbird development, these are the main channels.
  1. TB-Planning: This mailing list is higher level topics like: the future of Thunderbird, potential features, and changes that you would like to see happen. It is also used to discuss a variety of broader issues around community and governance of the project.
  2. Topicbox: A moderated mailing list for discussing engineering plans for Thunderbird. It is a place where you can raise questions and ideas for core Thunderbird development.
  3. Add-on Developers: A list for Thunderbird add-on developers and aspiring add-on developers to ask questions and share knowledge.
Chat
If you want to ask questions in real-time about how to hack on Thunderbird, you can join our development chat channel at #maildev:mozilla.org
About
Developer documentation for Thunderbird contributors.
developer.thunderbird.net
Resources
Readme
Activity
Stars
0 stars
Watchers
0 watching
Forks
0 forks
Report repository
Releases
Packages
Contributors

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
BranchesTags
Repository files navigation
DescriptionThunderbird is a powerful and customizable open source Email client with millions of users. It is based on the Mozilla platform that Firefox is also built on. These docs teach you how to contribute!
About Thunderbird
I Want to Start Hacking
This page has some information on where to get information and how to get plugged into the Community. If you are ready to start hacking, head over to one of the following sections.
Contributing to Thunderbird
Get all the information you need to set up your development environment and get ready to hack on Thunderbird.
{% page-ref page="thunderbird-development/getting-started.md" %}
Add-on Development
If you'd like to learn to develop add-ons for Thunderbird, check out our add-on documentation with examples, tips and links to relevant resources.
{% page-ref page="add-ons/about-add-ons.md" %}
Report Bugs and Request Features
Bugzilla
Thunderbird uses Mozilla's Bugzilla platform to report and track bugs. The site can also be used to generate enhancement bugs, which can be used for feature requests. If you want to become a contributor to Thunderbird, you will need an account on Bugzilla as you will submit patches through this platform.
Profiling Thunderbird Performance
Creating a performance profile can be useful for developers to find the causes of high CPU load or slowness in Thunderbird.
Thundernest on GitHub
If you want to contribute to the Thunderbird website, this documentation, or addons.thunderbird.net - you can find those repositories and their issue trackers on the Thundernest GitHub page. You'll need a GitHub account to contribute there.
Getting Plugged into the Community
We have a complete listing of the ways in which you can get involved with Thunderbird on our website. Below are some quick references from that page that you can use if you are looking to contribute to Thunderbird core right away.
Mailing Lists
If you want to participate in discussions about Thunderbird development, these are the main channels.
  1. TB-Planning: This mailing list is higher level topics like: the future of Thunderbird, potential features, and changes that you would like to see happen. It is also used to discuss a variety of broader issues around community and governance of the project.
  2. Topicbox: A moderated mailing list for discussing engineering plans for Thunderbird. It is a place where you can raise questions and ideas for core Thunderbird development.
  3. Add-on Developers: A list for Thunderbird add-on developers and aspiring add-on developers to ask questions and share knowledge.
Chat
If you want to ask questions in real-time about how to hack on Thunderbird, you can join our development chat channel at #maildev:mozilla.org
About
Developer documentation for Thunderbird contributors.
developer.thunderbird.net
Resources
Readme
Activity
Stars
0 stars
Watchers
0 watching
Forks
0 forks
Report repository
Releases
Packages
Contributors

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

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DescriptionThunderbird is a powerful and customizable open source Email client with millions of users. It is based on the Mozilla platform that Firefox is also built on. These docs teach you how to contribute!
About Thunderbird
I Want to Start Hacking
This page has some information on where to get information and how to get plugged into the Community. If you are ready to start hacking, head over to one of the following sections.
Contributing to Thunderbird
Get all the information you need to set up your development environment and get ready to hack on Thunderbird.
{% page-ref page="thunderbird-development/getting-started.md" %}
Add-on Development
If you'd like to learn to develop add-ons for Thunderbird, check out our add-on documentation with examples, tips and links to relevant resources.
{% page-ref page="add-ons/about-add-ons.md" %}
Report Bugs and Request Features
Bugzilla
Thunderbird uses Mozilla's Bugzilla platform to report and track bugs. The site can also be used to generate enhancement bugs, which can be used for feature requests. If you want to become a contributor to Thunderbird, you will need an account on Bugzilla as you will submit patches through this platform.
Profiling Thunderbird Performance
Creating a performance profile can be useful for developers to find the causes of high CPU load or slowness in Thunderbird.
Thundernest on GitHub
If you want to contribute to the Thunderbird website, this documentation, or addons.thunderbird.net - you can find those repositories and their issue trackers on the Thundernest GitHub page. You'll need a GitHub account to contribute there.
Getting Plugged into the Community
We have a complete listing of the ways in which you can get involved with Thunderbird on our website. Below are some quick references from that page that you can use if you are looking to contribute to Thunderbird core right away.
Mailing Lists
If you want to participate in discussions about Thunderbird development, these are the main channels.
  1. TB-Planning: This mailing list is higher level topics like: the future of Thunderbird, potential features, and changes that you would like to see happen. It is also used to discuss a variety of broader issues around community and governance of the project.
  2. Topicbox: A moderated mailing list for discussing engineering plans for Thunderbird. It is a place where you can raise questions and ideas for core Thunderbird development.
  3. Add-on Developers: A list for Thunderbird add-on developers and aspiring add-on developers to ask questions and share knowledge.
Chat
If you want to ask questions in real-time about how to hack on Thunderbird, you can join our development chat channel at #maildev:mozilla.org
About
Developer documentation for Thunderbird contributors.
developer.thunderbird.net
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