Dennis Ritchie, the inventor of C programming language and co-developer of Unix, died after a long, unspecified illness Wednesday. He was 70.

Dennis Ritchie poses after receiving the 2011 Japan Prize at Bell Labs headquarters in Murray Hill, N.J., in May. (Victoria Will/AP Images for Japan Prize Foundation)

After news of Ritchie’s death broke, words of remembrance came in for the man known to many as “dmr,” which was his e-mail address at Bell Labs, where he spent most of his career.

Many pointed out that Ritchie’s creation of the C programming language was a seminal moment for information technology. The technology Web site ZDNet wrote Thursday that the language is “at the heart of programming — and in the hearts of programmers.” It also remains the second most popular programming language in the world.

Ritchie’s co-development of Unix, a multitasking, multi-user computer operating system, has since inspired many descendent operation systems. Amazon’s chief technology officer, Werner Vogels, wrote in a tribute to Ritchie Thursday that although Unix works simply, “you have to be a genius to understand the simplicity — Dennis Ritchie, who was a genius, RIP.”

Rob Pike, a Google engineer and former colleague of Ritchie’s, wrote in a post Thursday that Ritchie “was a quiet and mostly private man . . . but he was also my friend, colleague, and collaborator, and the world has lost a truly great mind.”

ZDNet praised Ritchie for a lifelong focus on making software that “satisfied the intellect, while freeing programmers to create their dreams.”

Jeong Kim, president of Alcatel-Lucent Bell Labs, released a statement that said that Bell was in mourning for Ritchie’s death, because he “was truly an inspiration to all of us.”

On Twitter, a self-described economist and “avid user” of Linux, a variant of Unix, wrote Thursday, inspiring dozens of retweets:

Many others wrote that they owed their hobbies, careers and lives to Ritchie, and then signed off with a “RIP Dennis, you were awesome.”