On June 21, 2004 Apple announced Apple Remote Desktop 2 (released in July), which was designed to use the VNC protocol (with many private extensions) instead of Apple's original ARD protocol. This allows the ARD administration software to observe and control any computer running VNC-compatible server software (such as Windows and Unix systems) not just Macs and conversely allowing standard VNC viewing software to connect to any Mac with the ARD 2 software installed and VNC access enabled. This version also uses the Transmission Control Protocol (TCP) for most functions (on ports 5900 and 5988), which is designed to be more reliable than the UDP used in ARD 1. Another significant addition to ARD 2 was the Task List, that allows remote tasks to be queued and monitored, reporting their status (such as Succeeded or Failed). This release also dropped support for older versions of the Mac OS, requiring 10.2.8 or higher.