Mac OS X 10.1.3 is the third update for Mac OS X 10.1 "Puma". It is an update that improves the reliability of Mac OS X application programmes, includes important security features, and adds new and updated support for Digital Hub peripherals. Its build number is 5Q45 (5Q83 if you bought a new iMac G3 or iMac G4 with the OS already installed). Major support extensions came in the field of CD disc recording. Support was expanded for QPS, EZQuest, LaCie, Yamaha, MCE Technologies and Sony devices.