Apple’s CUPS Transition: From GPL to Apache and the Future with OpenPrinting

As early as 2007, Apple acquired the Linux open‑source printing system CUPS, and in 2017 it decided to stop developing CUPS under the GPL, moving it to the Apache 2.0 license. Besides Linux, this open‑source printing system is also widely used on Unix and macOS. However, after the chief CUPS developer left Apple at the end of 2019, development seemed to stall. Fortunately, a new chapter for CUPS is about to begin.

Recently, Michael Sweet, the founder of CUPS and former Apple employee, presented this change at the Open Printing Summit, stating that Apple has decided to cease further development of CUPS and that upstream development has been transferred to the OpenPrinting project. Sweet admitted that when he left Apple, the company was no longer actively developing CUPS.

Nevertheless, Sweet has a contract with Apple that requires him to pull important bug fixes from the OpenPrinting CUPS branch back into Apple’s macOS CUPS codebase. Future Apple CUPS will continue to receive these bug fixes from OpenPrinting, but Apple is no longer interested in adding new features.

OpenPrinting is currently working on CUPS 2.4, which adds AirPrint/Mopria compatibility, OAuth 2.0/OpenID authentication, pkg‑config support, Snapcraft support, TLS improvements, and various other enhancements; OpenPrinting has effectively become the new upstream for CUPS.

CUPS 3.0 is still being planned, with new server capabilities and a re‑architecture of this long‑running printing server. More details can be found in Michael Sweet’s presentation slides.