Review for Provider for Exchange ActiveSync by strawpants
Rated 5 out of 5 stars
This addon is a big relief, as it allows me to keep a central oversight of my mix of caldav, ics and MS-exchange calendars in thunderbird.
It's still depressing that MS has been refusing to support caldav out of the box, but I'm grateful that the developer took the initiative to create this functional workaround.
To create your own collections, you must have a Mozilla Add-ons account.