It features a graphical user interface (GUI), a mouse, Ethernet networking, and the ability to run multiple applications simultaneously.

[6][7] The first machines were introduced on March 1, 1973,[8] and in limited production starting one decade before Xerox's designs inspired Apple to release the first mass-market GUI computers.

The Alto is contained in a relatively small cabinet and uses a custom central processing unit (CPU) built from multiple SSI and MSI integrated circuits.

Industrial Design and manufacturing was sub-contracted to Xerox's Special Programs Group in El Segundo, whose team included program manager Doug Stewart, operations manager Abbey Silverstone, and industrial designer Bob Nishimura.

An initial run of 30 units was produced by the Special Programs Group, working with John Ellenby at PARC and Stewart and Silverstone at El Segundo, who were responsible for re-designing the Alto's electronics.

[12] The 2004 Charles Stark Draper Prize was awarded to Thacker, Alan C. Kay, Butler Lampson, and Robert W. Taylor for their work on Alto.

Mass storage is provided by a hard disk drive that uses a removable 2.5 MB one-platter cartridge (Diablo Systems, a company Xerox later bought) similar to those used by the IBM 2310.

Its speed was designed to be 3 Mbit/s because the microcode engine can not go faster and continue to support the video display, disk activity, and memory refresh.

The last two items had been introduced by SRI's On-Line System and the mouse was an instant success among Alto users, but the chord keyset never became popular.

These are photo-mechanical mice, first using white light, and then infrared (IR), to count the rotations of wheels inside the mouse.

Several other I/O devices were developed for the Alto, including a television camera, the Hy-Type daisywheel printer and a parallel port, although these were quite rare.

Despite its small memory size, many innovative programs were written for the Alto, including: There was no spreadsheet or database software.

Following the acquisition of an Alto, the White House information systems department sought to lead federal computer suppliers in its direction.

The Executive Office of the President of the United States (EOP) issued a request for proposal for a computer system to replace the aging Office of Management and Budget (OMB) budget system, using Alto-like workstations, connected to an IBM-compatible mainframe.

In December 1979, Apple Computer's co-founder Steve Jobs visited Xerox PARC, where he was shown the Smalltalk-76 object-oriented programming environment, networking, and most importantly the WYSIWYG, mouse-driven graphical user interface provided by the Alto.

The GUI was promptly integrating into Apple's products, first into the Lisa and then in the Macintosh, and Jobs recruited several key researchers from PARC.

[24] In 1980-1981, Altos were used by engineers at PARC and at the Xerox System Development Department to design the Star workstations.

[25] The Xerox corporate acquisition of Scientific Data Systems (SDS, later XDS) in the late 1960s had no interest to PARC.

These machines, based on the Wildflower architecture described in a paper by Butler Lampson, incorporated most of the Alto innovations, including the graphical user interface with icons, windows, folders, Ethernet-based local networking, and network-based laser printer services.

Xerox only realized its mistake in the early 1980s, after the Macintosh revolutionized the PC market via its bitmap display and the mouse-centered interface.