Researchers at PARC went on to invent the graphical user interface (GUI), the mouse, networked computers (the Ethernet), postscript, the laser printer and object orientated programming. If you are using a computer today it can can trace much of its origin back to Xerox PARC. You can read the full story in Chapter 6 Deadheads and Propeller Heads of my book. The complete story of PARC is fascinating and is told in detail in Dealers of Lightning: Xerox PARC and the Dawn of the Computer Age by Michale Hiltzik. Why Xerox didn't become the most powerful IT company in the world, bigger than Microsoft or IBM is a moot point. Some say incompetent, visionless, executives. But, hindsight gives us 20/20 vision and rather simply a photocopier company just couldn't grasp a future dominated by inexpensive software and computers.
PARC still exists and its website is here.