Edited sentence: As a result, some people call this class of interface a PARC User Interface (PUI) (note that PUI is also an acronym for perceptual user interface).It used a light-pen to guide the creation and manipulation of objects in engineering drawings.Ivan Sutherland developed a pointer-based system called the Sketchpad in 1963.Most modern general-purpose GUIs are derived from this system.The concept of hyperlinks was further refined and extended to graphics by researchers at Xerox PARC, who went beyond text-based hyperlinks and used a GUI as the primary interface for the Xerox Alto computer.The precursor to GUIs was invented by researchers at the Stanford Research Institute, led by Douglas Engelbart.They developed the use of text-based hyperlinks manipulated with a mouse for the On-Line System