Douglas Engelbart dies at age 88; computer visionary Douglas Carl Engelbart, who in the 1960s envisioned the power of interconnected computers to accelerate the pursuit of knowledge and solve the world's increasingly complex problems, laying the foundation for the modern computing age and the Internet, died in his sleep at his home in Atherton, Calif., on Tuesday night. He was 88. Engelbart's health had deteriorated in recent months and took a turn for the worse over the weekend, his daughter Christina Engelbart said in an email. For years, many in the scientific community dismissed Engelbart's revolutionary vision that would bring computers - then bulky machines operated by engineers and fed data on punch cards - into the digital age and into homes and offices the world over. His team of researchers toiled in relative obscurity until 1968, when Engelbart gave an hourlong presentation to leading technologists in San Francisco that telegraphed the future of computing. In what technology author Steven Levy dubbed "the mother of all demos," Engelbart demonstrated what could happen when computers talk to one another, showcasing innovations such as word processing, collaborative editing, hypertext links, video conferencing and desktop windows - 13 years before the IBM personal computer and 15 years before the Macintosh. It was also the world debut of the computer mouse, an idea driven by Engelbart's own desire for a handy device to interact with his computer screen. He and William English, a fellow engineer at the Stanford Research Institute, devised a wooden contraption that rolled on metal wheels and connected to the desktop with a cord that resembled the tail of a mouse. Apple's Steve Jobs would later turn the mouse into a huge commercial success, rolling it out to the masses in 1983 with the Lisa computer. Apple co-founder Steve Wozniak credits Engelbart and his landmark 1962 paper, "Augmenting Human Intellect: A Conceptual Framework" - a blueprint for how technology can harness information and help people collaborate with one another - "for everything we have in the way computers work today." The paper earned Engelbart funding from the Defense Department. "What he did was absolutely brilliant and so far ahead of its time back then," Wozniak said. He saw where the future was going to go. Engelbart's work inspired generations of scientists and was deployed by Microsoft's Bill Gates and Apple's Jobs to power their companies and fortunes. Yet Engelbart never shared in those riches, nor did he ever become a household name. He did not receive royalties for the mouse, which the research institute patented and later licensed to Apple, and, in later years, he struggled to get funding for his research, fading into the annals of computing history. Levy, author of "Insanely Great: The Life and Times of Macintosh, the Computer That Changed Everything," remembers visiting Engelbart in small offices half a block from where Apple was developing the Lisa and Macintosh computers. "He was in the shadow of the people who would get credit for his ideas and make billions of dollars from them," Levy said. Longtime friend Howard Rheingold said he paid a visit to Engelbart after a contractor had botched the remodel of his home near Stanford University. For years Engelbart, who lived next door to some of Silicon Valley's wealthiest, could not afford to fix the pervasive damage. Thick metal cables bolted to the studs stretched across the living room to hold up the walls, and some parts of the house could not be used. Yet it was his struggles to get funding for his research that troubled Engelbart. He wanted to help people solve problems, and he saw the world as having very significant problems. That is not something you can get a patent on, start a company or make a fortune on," said Rheingold, author of "Tools for Thought: The History and Future of Mind-Expanding Technology." Bill Gates' vision was a computer on every desk running Microsoft software. Doug had a much larger humanitarian vision. Engelbart was born Jan. 30, 1925, in Portland, Ore. He enrolled at Oregon State University but was drafted into the Navy before he graduated. While stationed as a radar technician in the Philippines in 1945, he read an article in the Atlantic Monthly by presidential science advisor Vannevar Bush that urged scientists to make knowledge more accessible. Inspired, Engelbart resolved to pursue a career in computer science. After the war, he returned to Oregon State and received a bachelor's degree in electrical engineering in 1948. In 1955, he got a doctorate in electrical engineering from UC Berkeley. Engelbart joined the Stanford Research Institute in 1957 as a researcher. In the early 1960s, he led a team developing tools for interactive computing. Within SRI, he founded the Augmentation Research Center, which was funded by the Air Force and the Defense Advanced Research Projects Agency (DARPA), the research arm of the Defense Department. In the early 1970s, his laboratory was one of those that hosted the ARPAnet, the forerunner of the Internet. It also hosted the Network Information Center, which would eventually become officially responsible for doling out Internet domain names. For all of his work to promote collaboration, Engelbart was known in the industry as a control freak, and many of his colleagues eventually moved on to new research centers such as Xerox's Palo Alto Research Center and to companies such as Apple to develop his ideas for the mainstream. DARPA funding began to dry up, and, in the late 1970s, Engelbart's research group was bought by a company called Tymshare. It was sold again in the early 1980s to defense contractor McDonnell Douglas. In 1989, Engelbart created the Bootstrap Institute with his daughter Christina. The organization gave management seminars and received DARPA funding to do some work for the military. In 2000, Engelbart received the National Medal of Technology and Innovation. Engelbart retired in 2008, and the organization is now known as the Doug Engelbart Institute. Friends say he never lost his playful sense of humor, even after his first wife, Ballard, died in 1997 after 46 years of marriage. It was a long-running family joke that he used to give her science lectures when she had trouble sleeping. He also made up science-fiction stories to entertain his kids. Though he often had his head nestled deep inside a book, Engelbart enjoyed the outdoors and spent time tending his organic garden, hiking, camping, bike riding and sailing. He also raised ducks, earthworms and bees. He is survived by his second wife, writer and producer Karen O'Leary Engelbart, whom he married in 2008; daughters Gerda, Diana and Christina; a son, Norman; and nine grandchildren.