Thunderbird, the long-running email and calendar application from Mozilla, has spent this year reorganizing and working on major updates. Now the development team is starting to show off the next big upgrade, codenamed "Thunderbird Supernova."

Related: What's New in Mozilla Thunderbird 102

Thunderbird 102 was released in June 2022 as the first phase of the app's revamp, with an updated address book, a new Spaces Toolbar (similar to the app switcher on Gmail and Outlook), and a streamlined account setup process. Mozilla previously said a major design update would arrive in 2023, which the development team has given the codename "Supernova." The actual version number is expected to be 114 or 115, matching whichever Firefox release is out by then.

The first glimpse of the Supernova update has been published on the Thunderbird blog: a work-in-progress mockup of the new calendar design. Don't worry, it still looks like a calendar, but Mozilla has cleaned it up. Weekends can be hidden to save screen space, and you can set which days are defined as the weekend. The top toolbar will be fully customizable, and even though the "relaxed" density with plenty of space between buttons will be the default, a tighter interface will also be available.

Thunderbird calendar mockup screenshot
Thunderbird

Mozilla said in a blog post, "We've intentionally made this calendar pretty busy to demonstrate how the cleaner UI makes the calendar more visually digestible, even when dealing with many events. Dialogs, popups, tool-tips, and all the companion calendar elements are also being redesigned. Many of the visual changes will be user-customizable."

Thunderbird "Supernova" is still on track to be released next year, while work continues to update the K-9 Mail app for Android into an official Thunderbird client. You can download the current version from the project's website.

Source: Thunderbird