Ward Christensen, a pioneering computer scientist credited with creating the first online bulletin board—a precursor to today’s messaging apps and social media—passed away on October 11 at his Rolling Meadows, Illinois home at the age of 78. His brother, Donald, confirmed that he died from a heart attack.

In the summer of 1975, while working at IBM in Chicago, Christensen joined the Chicago Area Computer Hobbyists’ Exchange (CACHE) and met fellow enthusiast Randy Suess. They discussed developing a system to transmit information between computers over telephone lines.

On January 16, 1978, a heavy snowstorm stranded Christensen at home. He called Suess to suggest they use the time to start building their messaging system, considering enlisting more club members, but Suess believed it would complicate matters. “Forget the club. It would just be management by committee,” Suess told Christensen, who recounted this to The New York Times in 2009. “It’s just me and you. I’ll handle the hardware, you take care of the software.”

Using a spare computer, some software, and a modem, they created a system enabling club members to exchange information. By connecting their home computers, users could upload messages, such as meeting announcements and project ideas, for others to access.

Christensen envisioned their project as a digital version of community bulletin boards found in grocery stores, where people post local event flyers. “I patterned the software after the cork-board-and-push-pins type of bulletin board,” he noted years later.

When Suess suggested naming it “the Computer Elites’ Communication Project,” Christensen disagreed, and they settled on the Computerized Bulletin Board System, or C.B.B.S.

As news of their creation spread through word of mouth and industry publications, computer bulletin boards emerged nationwide, enabling users to share messages, games, and software—laying the groundwork for modern social media platforms like Reddit, TikTok, Facebook, and YouTube.

“The concept of ordering a computer and using it to connect with others online began with these two guys,” stated Jason Scott, a computer history archivist who created an online documentary about C.B.B.S. “They believed, ‘Anyone can do this.’”

Born on October 23, 1945, in West Bend, Wisconsin, Christensen’s father was a safety director for an aluminum company, while his mother sold encyclopedias. Known for his programming skills, he was also a hands-on tinkerer from a young age, building a computer adding machine in his teens.

He briefly attended the University of Wisconsin, Madison, before transferring to a small college where he studied physics and chemistry. During his senior year, he learned that IBM was recruiting on campus, prompting his mother to buy him a suit for the interview. He joined IBM in 1968 and remained with the company until his retirement in 2012.

Initially disappointed that his department lacked computers, he soon became interested in acquiring his own. With the rise of home computers, he was among the first hobbyists to purchase them and join CACHE, collaborating on hardware and software projects.

In 1977, he developed the XMODEM protocol for transmitting files over phone lines, which would later be utilized in C.B.B.S. When he and Suess launched their messaging system, it was a makeshift assembly, as Christensen described it. They decided to host the system in Suess’s Chicago home for easier access.

Their creation was detailed in an article Christensen wrote for Byte, a hobbyist magazine, and by the time they retired the system, it had received over half a million calls.

Christensen is survived by his brother, nieces Carin and Dana, and his partner Debra Adamson. Despite their significant achievement, neither he nor Suess profited greatly or gained fame, but Christensen took pride in their work, even proudly displaying “XMODEM” on his license plate for many years.