On March 28, 1945, the first day of Passover, George Heller packed his backpack with his few remaining belongings and began a forced march from Burgenland, Austria, toward the Mauthausen concentration camp. Once he arrived, the emaciated 21-year-old was convinced he would be killed by machine-gun fire–either at the bottom or the top of the hill that marked the camp’s entrance.

“I asked myself, do I want to lie down and die right here or climb to the top and potentially die up there?” he says. “Even though I had very little strength, I chose to climb.”

Sixty-five years later, Heller is still climbing. In fact, he recently celebrated his 86th birthday by scaling the 20-foot climbing wall at the YMCA in Palo Alto, CA, where he has gone weekly for the past 15 years. At the top of that wall, Heller has posted a banner printed from his own computer that declares, “It’s possible!”

It’s this optimistic spirit of perseverance that he says kept him alive and propelled him forward, from his native Hungary, where his family and community were devastated by the Holocaust, to the United States, MIT, and a successful career as a computer scientist and advocate for computer education.

Sitting in his living room in Menlo Park, CA, Heller picks up a water glass as exhibit A. “I often ask people to tell me, is this half full or half empty?” he says. His wife, Iby, whose family fled from Belgium when the Germans invaded, serves tea and smiles. To him, the glass is half full, of course. He pulls out two more banners, proclaiming “Keep on going no matter what” and “I made it this far!”

Though these slogans may be simple, ­Heller’s journey has been anything but. It began in Budapest, where he was born in 1924 to a father who was a typesetter and a mother who managed the family business. His parents, although not educated beyond the eighth grade themselves, stressed the importance of study for their three children. As a first grader, Heller spoke Hungarian and German fluently, and also some Hebrew. He later went on to study Latin, English, and French. “My parents always told me that education was the one thing that no one can ever take away from you,” he says.

Heller had just completed an apprenticeship to become a journeyman typesetter when political events began to permanently alter his world. Hungary had allied itself with Nazi Germany and taken part in the invasion of the Soviet Union, and the government began imposing increasingly harsh restrictions on Jews. As Soviet forces began inflicting heavy casualties, it sought to quit the war, prompting a German occupation in 1944. That year, Heller was drafted into a forced-labor unit in Budapest for his mandatory military service. Meanwhile, many of the city’s Jews were being squeezed into a ghetto, and still others were sent to their deaths in Auschwitz.

“Things were getting progressively worse for Jews in Hungary,” he says. “No one could believe that a civilized country like Germany could be behaving in this way.”

Heller’s brother died on the Russian front, his sister was murdered in the Budapest ghetto, and many friends and members of his extended family were killed in concentration camps. But Heller was sent by cattle car to Austria, where he worked in a labor camp beside 150 other men under supervision of the Waffen SS for five months. It wasn’t until the end of the war that he found himself at Mauthausen; although its crematorium had already been shut down, he describes the camp as “a brutal place” in which people were dying of exhaustion and illness.

The American army arrived to liberate those held at Mauthausen and surrounding camps on May 5, 1945. “I was 21 years old, I had no hair, and I weighed 80 pounds,” he recalls. “Even in my sorry state, I knew that I had made it.”

Heller soon convinced those running the United Nations displaced-persons camps in Wells and Linz, Austria, that his language skills would make him useful as a translator. He worked for a year for the U.N. Relief and Rehabilitation Administration before he secured a rare visa to the United States.

Once he arrived, Heller lived with an aunt in the Bronx and worked as a typesetter and a busboy before he was awarded a scholarship to Temple University in Philadelphia. After graduating with a bachelor’s degree in management and marketing, he returned to New York, where he met and married Iby–whose mother was also originally from Hungary–and took a job as a manager at a car parts manufacturer in Brooklyn. “I was still looking for the right occupation, and this wasn’t it for me,” he says.

Heller sent a letter to MIT. “I realized that the future included understanding technology, and the best place to get that training was at MIT,” he says. When he called the school, an admissions officer said, “You’re 30 years old. Do you want to be a freshman?” Heller replied that he did, but he had to wait another year and apply a second time before he was accepted. In Cambridge, he lived with his wife and his mother, who had survived the Holocaust and made her way to the United States. He describes those years as “all work and no play.” On occasion, however, he and Iby entertained fellow students with lessons in making Hungarian apple strudel, his favorite dessert.

Heller’s affinity for languages again served him well at MIT, where he completed a senior thesis on the use of computers for language translation. He received two bachelor’s degrees, one in electrical engineering and the other in the humanities.

With 16 job offers in hand after graduation, Heller took a position at IBM in Kingston, NY–the start of what would be a 30-year career in computer science. He worked to build operating systems and develop new computer languages, and he also developed a passion for computer education. In 1960, after IBM transferred him and his family to Washington, DC, he started a volunteer project with the aim of teaching high-school students about computers. “Students were selected through what I called the ‘gleam-of-the-eye test,’ ” he says.

This enthusiasm got a more significant outlet when Heller became national education chairman of the Association for Computing Machinery. And with small children of his own at home, he worked to introduce computers to children as young as preschoolers. In the early 1960s, he invited children to use a specially designed graphics program called Sketch to draw pictures using IBM 360 computers. “People thought I was nuts at the time,” he says. “But I saw this as my opportunity to do something for the next generation.” Soon, Heller’s zeal for teaching computer science to young people began catching on. A Washington Post column from December 1961 lauded him for mentoring area young people and credited him with “organizing a most successful series of computer courses for high school students.”

Heller retired from IBM in 1990, but he has yet to slow his pace. He speaks often to local high-school students, using his life story to teach about coping with adversity. Also an active member of the MIT Educational Council, he has helped recruit new students since 1968. He and Iby both teach courses in computer subjects at a nearby senior center. They visit their four children (two of whom are also MIT graduates), who now have nine children of their own. And they keep telling their stories–to students on a recent trip to Eastern Europe, and to their friends, who can sometimes be found gathered around their dining-room table, stretching pastry to make the strudel that remains his favorite dessert.

“When I show people how they can take a small ball of dough and stretch it as long and wide as a dining-room table, they are amazed,” Heller says. “It’s another example of the philosophy that has guided me my entire life: it really is true that anything is possible.”