OpenPrinting Now Developing Upstream CUPS, Apple Bows Out
Apple has decided not to pursue feature development further on CUPS and upstream feature development has been effectively transferred to the OpenPrinting project. CUPS founder and former Apple employee Michael Sweet presented on this change at this month's Open Printing Summit. Sweet acknowledged that Apple stopped actively developing CUPS when he left the company. But now he's been contracted by Apple to apply important bug fixes from the OpenPrinting fork of CUPS back to the Apple CUPS code-base for macOS. Apple CUPS will continue seeing these bug fixes pulled in from OpenPrinting CUPS but Apple is no longer interested in feature development on this print server.
OpenPrinting now is working towards a CUPS 2.4 release with AirPrint/Mopria compatibility, OAuth 2.0 / OpenID authentication, pkg-config support, Snapcraft support, TLS improvements, and a variety of other feature improvements with now effectively being the new CUPS upstream.
Plans for a CUPS 3.0 are even being drawn with new server capabilities and other re-architecting of this long-running print server. More details on this renewed CUPS work via this slide deck from Michael Sweet.
Since leaving Apple, Sweet has also been developing the modern PAPPL printer application framework.