IRIX 4.0
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IRIX 4.0, introduced in September of 1991 with the IRIS Indigo workstation was the first version of IRIX to be officially named "IRIX." Replacing the 4Sight NeWS-based 4D1-3.x system, X11R4 using the IRIS Desktop (later called IRIX Interactive Desktop), and was the first version to be released on CD, as opposed to QIC tape.
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