Mozilla Thunderbird

Mozilla Thunderbird
Mozilla Thunderbird
	Logo used since 2023
	Mozilla Thunderbird 115 showing the mail inbox
Developer(s)	Mozilla Foundation (formerly Mozilla Messaging); MZLA Technologies Corporation;
Initial release	July 28, 2003
Stable release	128.11.1esr / 10 June 2025
Preview release	140.0beta (30 May 2025) [±]
Repository	https://hg-edge.mozilla.org/
Written in	C, C++, JavaScript, CSS, Rust, XUL, XBL
Engines	Gecko, SpiderMonkey
Operating system	Windows 10 or later; macOS 10.15 or later; FreeBSD; Linux; Android
Size	50 MB
Available in	65 languages
	List of languages Albanian, Arabic, Armenian, Asturian, Basque, Belarusian, Breton, Bulgarian, Catalan, Chinese (Simplified), Chinese (Traditional), Croatian, Czech, Danish, Dutch, English (British), English (US), Estonian, Finnish, French, Frisian, Gaelic (Scotland), Galician, German, Greek, Hebrew, Hungarian, Icelandic, Indonesian, Irish, Italian, Japanese, Kabyle, Korean, Lithuanian, Lower Sorbian, Norwegian (Bokmål), Norwegian (Nynorsk), Polish, Portuguese (Brazilian), Portuguese (Portugal), Romanian, Romansh, Russian, Serbian, Sinhala, Slovak, Slovenian, Spanish (Argentina), Spanish (Spain), Swedish, Turkish, Ukrainian, Upper Sorbian, Vietnamese, Welsh.
Type	Email client, personal information manager, instant messaging client, news client, feed reader
License	MPL-2.0
Website	www.thunderbird.net

Mozilla Thunderbird is a free and open-source^[8] email client that also functions as a personal information manager with a calendar and contactbook, as well as an RSS feed reader, chat client (IRC/XMPP/Matrix), and news client. Operated by MZLA Technologies Corporation, a subsidiary of the Mozilla Foundation, Thunderbird is an independent, community-driven project that is managed and overseen by the Thunderbird Council, which is elected by the Thunderbird community. As a cross-platform application, Thunderbird is available for Windows, macOS, FreeBSD, Android, and Linux. The project strategy was originally modeled after that of Mozilla's Firefox, and Thunderbird is an interface built on top of that Web browser.^[9]

^ "Release Notes". June 10, 2025. Retrieved June 10, 2025.
^ "Release Notes". May 30, 2025. Retrieved May 31, 2025.
^ "Firefox's addons are written in JavaScript". Rietta. Archived from the original on August 4, 2009. Retrieved December 19, 2009.
^ "Firefox uses an "html.css" stylesheet for default rendering styles". David Walsh. July 10, 2008. Retrieved December 19, 2009.
^ "Thunderbird Mobile". www.thunderbird.net. Mozilla Messaging. Retrieved May 9, 2025.
^ Cite error: The named reference languages was invoked but never defined (see the help page).
^ Mozilla Project Licensing Archived 2014-09-04 at the Wayback Machine Mozilla.org
^ "Debian and Mozilla – a study in trademarks". LWN.net. Retrieved September 18, 2010.
^ "Why We're Rebuilding The Thunderbird Interface From Scratch". MZLA Technologies Corporation. February 9, 2023. Retrieved February 11, 2023. Thunderbird is literally a bunch of code running on top of Firefox. All the tabs and sections you see in our applications are just browser tabs with a custom user interface.