The iCal format, first defined as a standard as RFC 2445 in 1998, is the universally accepted format for distributing calendar files, mainly used for distributing events.

As part of my QR code scanning app Scanula I added support for detecting events in scanned objects. Thanks to the fantastic libical and the Swift wrapper swift-ical it's fairly easy to parse an iCal feed, but adding it to iOS is a bit trickier.