Calibre is one of the great pieces of FOSS software, and demonstrates everything good about FOSS: it has regular updates; it’s been around for simply ages; it works really, really well; it gets updates and new features and yet has never in my memory had a breaking, non-backwards-compatible release… it’s stable; and it resists - in its way - the attempt by publishers to steal our rights and ownerships of our media.
I contribute donate to Calibre. I hope that Goyal has a successor lined up to take the helm who can continue such an outstanding contribution when he finally retires from the project.
Edit: clarification
It’s pretty nice, although IME it’s really crashy.