An Open-Source Effort to Amalgamate Windows and Mac OS X
XQuartz is an open-source project that is committed toward making an x.org X Window Systems variant that runs smoothly on Apple’s Mac OS X. In combination with supporting applications and libraries, it creates the X11.app, which was shipped with the different OS X versions by Apple. The XQuartz installation comprises several individual software pieces that have numerous licenses. These licenses and their components are being discussed online on the official X.Org licenses page. The non-official updates available make it easy for users to remain up-to-date with the advancements made within the open source realm where Apple is also a participant.
