On December 20, 2001, Apple Inc. released Mac OS X 10.1.2, the second update to Mac OS X 10.1 "Puma". The build number is 5P48 (5P63 for summer 2001 and flat-panel iMacs, as well as "Quicksilver" (2002) Power Mac G4s, and PowerBook G4s with Gigabit Ethernet).
The main enhancements in this update include improvements, new functionality, and expanded peripheral support for Mac OS X.
Updated and new USB and FireWire device support, including FireWire-based digital cameras, were included with this update. PCMCIA (PC Card) storage devices and media readers got a functionality enhancement as well. For PowerBooks with FireWire ports, this update finally restored IrDA modem support.
AirPort 2.0, Apache web server 1.3.22, and AppleScript 1.8 (which supports applications created with AppleScript Studio, part of the December 2001 Developer Tools package) also form part of the new update.