I've found some neat libraries regarding email and WebRTC meetings but I can't find anything on calendar sync for the life of me. I have a UI in mind for my own calendar app but I can't find a good open source framework or library that does calendar sync with both Google Calendar (personal), Office365 (work), and CalDAV (also work).
I've found a library that (kind of) does Google Calendar by itself and a slew of projects regarding Office365's API that don't really seem to have much in the way of reliability. Haven't found anything in the way of CalDAV.
Hoping someone can recommend a good calendar sync framework, preferably with JS or Rust bindings?
Things like DAVdroid provide a syncing ability for Cal/CardDAV to Android.
There is evolution-data-server and SyncEvolution for regular GNU/Linux.
Good luck in building something lighterweight, I'd be keen to move to it from NextCloud too :)