Dennis M. Ritchie | Software pioneer, 70

Dennis M. Ritchie, 70, who helped shape the modern digital era by creating software tools that power everything from search engines such as Google to smartphones, was found dead Wednesday at his home in Berkeley Heights, N.J.

Mr. Ritchie, who lived alone, had been in frail health in recent years after treatment for prostate cancer and heart disease, said his brother Bill.

In the late 1960s and early '70s, working at Bell Labs, Mr. Ritchie made a pair of lasting contributions to computer science. He was the principal designer of the C programming language and codeveloper of the Unix operating system, working closely with Ken Thompson, his longtime Bell Labs collaborator.

The C programming language, a shorthand of words, numbers and punctuation, is still widely used today, and successors like C++ and Java build on the ideas, rules and grammar that Mr. Ritchie designed.

The Unix operating system has similarly had a rich and enduring impact. Its free, open-source variant, Linux, powers many of the world's data centers, such as those at Google and Amazon, and its technology serves as the foundation of operating systems, like Apple's iOS, in consumer computing devices.

"The tools that Dennis built - and their direct descendants - run pretty much everything today," said Brian Kernighan, a computer scientist at Princeton University who worked with Mr. Ritchie at Bell Labs.

Mr. Ritchie was born in Bronxville, N.Y., and attended high school in Summit, N.J. He then went to Harvard, where he majored in applied mathematics.

Mr. Ritchie joined Bell Labs in 1967, and soon began his fruitful collaboration with Thompson on both Unix and the C programming language. - N.Y. Times News Service