Mark Weiser

Mark Weiser (1952-1999) was an American computer scientist at the Xerox Palo Alto Research Center (PARC), where he headed the Computer Science Laboratory from 1988 to 1994 and later served as chief technologist. He coined the term "ubiquitous computing" in 1988 for a program of research into many computers spread through the physical environment but made "effectively invisible" to their users, and he set out the idea for a general audience in the September 1991 Scientific American article "The Computer for the 21st Century".

Weiser defined ubiquitous computing in deliberate contrast to virtual reality. His 1991 article called virtual reality "perhaps most diametrically opposed to our vision", because it "attempts to make a world inside the computer", and his group's web page on the subject stated that "ubiquitous computing is roughly the opposite of virtual reality". His paper on the computer science of ubiquitous computing appeared in the July 1993 special issue of Communications of the ACM on computer-augmented environments, the same issue that carried early augmented reality papers by Steven Feiner and Ronald Azuma. He died in 1999 at the age of 46.

Reviewed 15 October 2026. Biographical dates, career positions, awards, publication details and quoted passages checked against the Stanford finding aid, SIGMOBILE 1999 award page, Salon obituary, archived ubiq.com pages, OCR of the 1991 Scientific American scan, the 1993 CACM preprint, DBLP and Crossref. About review dates.

Early life and education

According to the finding aid for his papers at Stanford University Libraries, Weiser was born in Chicago, Illinois, in 1952 and moved with his family to Mount Carroll, Illinois, at the age of four. At fourteen the family moved to Ithaca, New York, and a year later to Stony Brook, New York, where he finished high school. He never received a bachelor's degree. He earned an M.S. (1976) and a Ph.D. (1979) in Computer and Communication Sciences at the University of Michigan. While in Ann Arbor he worked as a programmer for Omnitext, Inc. (1970-1975), was a research assistant at the university (1974-1979), and co-founded two companies, Cerberus Inc. and Portable Information Systems, Ltd. (both 1973-1976).

Career

University of Maryland

Weiser joined the Computer Science Department of the University of Maryland in 1979. He was an assistant professor from 1979 to 1984, laboratory director from 1981 to 1984, associate professor from 1984 to 1987, and associate chairman of the department from 1986 to 1987. His research in this period included program slicing; his paper "Program Slicing" appeared in IEEE Transactions on Software Engineering in 1984. According to the SIGMOBILE award biography, his work "Program Slicing" received the "Best Paper Ten Years Later" award of the ACM and IEEE International Conference on Software Engineering in 1993.

Xerox PARC

Weiser joined Xerox PARC in May 1987 as a member of the research staff and became a principal scientist in 1988. He headed the Computer Science Laboratory from November 1988 to December 1994. His author note in the 1991 Scientific American article described him as head of that laboratory, working on "the next revolution of computing after workstations, variously known as ubiquitous computing or embodied virtuality", and said his most recent technical work had been on garbage collection. On his personal home page he wrote that he stepped down in 1994 to found a startup and returned in August 1996 as chief technologist of PARC. The 1999 SIGMOBILE award biography gives the post as chief technology officer, held from 1996 to 1999.

Outside PARC he was elected to the board of the Computing Research Association (CRA) for 1992-1994 and founded the CRA series of annual conferences for heads of industrial computer science research laboratories; he also served as an associate editor of IEEE Transactions on Software Engineering (1992-1994) and was program chair of the fifteenth ACM Symposium on Operating Systems Principles (SOSP) in December 1995.

Ubiquitous computing

Weiser first articulated ubiquitous computing in 1988 at PARC's Computer Science Laboratory. He wrote that the idea came from "contemplating the place of today's computer in actual activities of everyday life", drawing on anthropological studies of work, and that the research method was to build working prototypes in sufficient quantity for everyday use, with the researchers and a few colleagues as the test subjects. The Scientific American article opened with the sentence "The most profound technologies are those that disappear."

The PARC prototypes came in three sizes, which Weiser called tabs, pads and boards: "inch-scale machines that approximate active Post-it notes, foot-scale ones that behave something like a sheet of paper (or a book or a magazine) and yard-scale displays that are the equivalent of a blackboard or bulletin board". The stated goal for initial deployment was "hundreds of computers per room". The group's web page dates this first generation of devices to 1988-1994. In the 1993 Communications of the ACM paper Weiser described the ParcTab, a tab-sized device with a pressure-sensitive screen, three buttons and the ability to sense its position within a building, and the MPad, a pad-sized device with both infrared and radio communication, and noted that the first ubiquitous computing technology to be deployed, the Liveboard, had become a Xerox product. A fuller account of the ParcTab system, with Roy Want, Bill Schilit and other PARC colleagues, appeared in IEEE Personal Communications in December 1995.

Calm technology

With his PARC colleague John Seely Brown, Weiser wrote "Designing Calm Technology" (dated 21 December 1995), which argued that well-designed technology should move easily between the periphery and the center of a person's attention. Its opening example was the "Dangling String" by artist Natalie Jeremijenko, an 8-foot piece of plastic hung from a small ceiling-mounted motor wired to a nearby Ethernet cable, so that each bit of passing network traffic made the motor twitch. A version titled "The Coming Age of Calm Technology" was published in the 1997 Springer collection Beyond Calculation: The Next Fifty Years of Computing.

Severe Tire Damage

Weiser was the drummer of the rock band Severe Tire Damage. In June 1993 the band broadcast live audio and video worldwide over the Internet's MBone multicast system, which the SIGMOBILE biography and Salon both describe as a first for a band.

Views on virtual reality

Weiser repeatedly used virtual reality as the foil for his own program. In the 1991 Scientific American article he described it as an attempt "to make a world inside the computer", with users wearing goggles, gloves or bodysuits, and wrote that although it might help people explore realms otherwise inaccessible, "virtual reality is only a map, not a territory". It excluded "desks, offices, other people not wearing goggles and bodysuits, weather, trees, walks, chance encounters". In his words, it "focuses an enormous apparatus on simulating the world rather than on invisibly enhancing the world that already exists". He added that the contrast was strong enough that some at PARC used the term "embodied virtuality" for the process of drawing computers out of their electronic shells.

The 1993 Communications of the ACM paper gave a more qualified view. Weiser wrote that when he started the ubiquitous computing work in 1988, virtual reality came closest to the principles his group believed important, since in its ultimate form it makes the computer effectively invisible by taking over the user's senses. He called VR extremely useful for scientific visualization and entertainment, but identified two flaws for everyday use: it could not then produce a convincing simulation at reasonable cost, and its goal was to fool the user into leaving the everyday physical world behind. His group's web page summarized the difference this way: "Where virtual reality puts people inside a computer-generated world, ubiquitous computing forces the computer to live out here in the world with people."

That paper appeared in a Communications of the ACM issue on computer-augmented environments, introduced by Pierre Wellner, Wendy Mackay and Rich Gold under the heading "Back to the Real World". The issue also contained "Knowledge-based augmented reality" by Steven Feiner, Blair MacIntyre and Dorée Seligmann, Ronald Azuma's "Tracking requirements for augmented reality", Wellner's DigitalDesk paper and a two-page piece by Myron Krueger, "Environmental Technology: Making the Real World Virtual". Late in his career Weiser co-authored, with PARC colleague Daniel M. Russell, a CHI 98 session summary titled "The future of integrated design of ubiquitous computing in combined real & virtual worlds".

Death and legacy

Weiser died on 27 April 1999, aged 46. ACM SIGMOBILE gave him its 1999 Outstanding Contribution Award for his contributions to and leadership in ubiquitous computing; the principal nominating statement, by Randy H. Katz of the University of California, Berkeley, called his Scientific American and Communications of the ACM papers "true classics of the field". Stanford University Library and Xerox PARC each set up memorial web sites. His papers, a gift from his widow Victoria Reich in May 1999, are held by Stanford's Department of Special Collections and University Archives.

In 2001 ACM SIGOPS created the Mark Weiser Award, given to an individual who has shown creativity and innovation in operating systems research. In 2023 the University of Chicago Press published John Tinnell's biography The Philosopher of Palo Alto: Mark Weiser, Xerox PARC, and the Original Internet of Things.

Selected publications

Year	Title	Co-authors	Venue
1984	Program Slicing	None	IEEE Transactions on Software Engineering
1991	The Computer for the 21st Century	None	Scientific American
1993	Some Computer Science Issues in Ubiquitous Computing	None	Communications of the ACM
1995	An overview of the PARCTAB ubiquitous computing experiment	Roy Want, Bill Schilit, Norman Adams, Rich Gold, Karin Petersen, David Goldberg, John Ellis	IEEE Personal Communications
1995	Designing Calm Technology	John Seely Brown	Xerox PARC paper
1997	The Coming Age of Calm Technology	John Seely Brown	Beyond Calculation (Springer)
1998	The future of integrated design of ubiquitous computing in combined real & virtual worlds	Daniel M. Russell	CHI 98

See also

• Ubiquitous computing
• Spatial computing