Xerox PARC's Alto shows the first working GUI
A mouse, windows, and icons appear on screen years before any product used them
Quick facts
- Built at
- Xerox Palo Alto Research Center (PARC)
- First operational
- 1973
- Key features
- Mouse, overlapping windows, icons, bitmapped display
- Word processor
- Bravo, the first WYSIWYG text editor
What happened
Engineers at Xerox's Palo Alto Research Center built the Alto as a research machine to explore what they called personal, distributed computing rather than a product to sell. It combined a bitmapped display, roughly 600 by 800 pixels capable of showing varied fonts and layouts rather than only fixed characters, with a mouse and software that presented movable, overlapping windows and clickable icons, a genuinely visual way of using a computer rather than typing text commands. Its word processor, Bravo, is considered the first WYSIWYG ('what you see is what you get') editor, showing text on screen exactly as it would print. The system never sold in large numbers; Xerox gave away or sold a few thousand units mostly to research institutions.
Why it matters
Nearly every visual element of modern computing, the pointer, the window, the icon, the idea that a screen shows you what you will get on paper, debuted on the Alto years before Apple or Microsoft shipped anything comparable. Xerox's own 1981 commercial version, the Star, and later Apple's Macintosh both drew directly on what PARC had already built.
How we know
The Computer History Museum's own account of the Alto, in its Revolution exhibit, describes the mouse, the windows and icons interface, and the Bravo WYSIWYG editor from its historical and curatorial record.
Sources
- Computer History Museum (CHM Revolution). Xerox Alto · Reputable sourcecomputerhistory.org · The domain "computerhistory.org" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
- IEEE Spectrum. 50 Years Later, We're Still Living in the Xerox Alto's World · Peer-reviewedspectrum.ieee.org · The domain "spectrum.ieee.org" is on our Peer-reviewed registry. · Link is live and its text matches the event's key terms (Jul 2026)
See something wrong? . Corrections with a source get fixed fastest.
Part of a timelineThe Internet and Computing36 events · From a mechanical engine that never ran to a network that never sleepsView all →