Now the development team is starting to show off the next big upgrade, codenamed “Thunderbird Supernova.”
Don’t worry, it still looks like a calendar, but Mozilla has cleaned it up.
Dialogs, popups, tool-tips, and all the companion calendar elements are also being redesigned.
Thunderbird
Many of the visual changes will be user-customizable."
You candownload the current versionfrom the project’s website.
