In 1982, Warnock, along with Charles Geschke, established the San Jose-based company. He served as the CEO until 2000 and continued as the Chief Technical Officer until his retirement in 2001. For nearly three decades, he held the position of chairman of the board, sharing this role with Geschke for most of that period. Even after his retirement, Warnock remained on the company's board of directors. Charles Geschke, his co-founder, had previously passed away in 2021 at the age of 81.

The partnership between Warnock and Geschke began at Xerox Holdings Corp, where they were colleagues. Their initial product, PostScript, played a pivotal role in catalyzing the desktop publishing revolution.

Shantanu Narayen, the CEO of Adobe, expressed his deep appreciation for Warnock, not just as a mentor but also as a cherished friend in an email to the company's employees.

Before co-founding Adobe, John Warnock had a distinguished career. He was a principal scientist at Xerox Palo Alto Research Center and had held various positions at Evans & Sutherland Computer, Computer Sciences Corp., IBM, and the University of Utah, as outlined in the company's biography. He held a doctorate in electrical engineering, a master's degree in mathematics, and a bachelor's degree in mathematics and philosophy, all earned at the University of Utah.

John Warnock is survived by his wife, Marva, and their three children.