Two weeks ago, one of the greatest pioneers of the 21st century technology industry passed away. He was responsible for some of the most important technological innovations, and his work moulded the computer world into its current state. Dennis Ritchie was one of the greatest innovators of his time.
Ritchie’s death came only one week after the passing of Steve Jobs, making it difficult not to draw comparisons between the two. Jobs was an excellent businessman, with the knowledge and power to market any device to anyone at any time. He pushed for the absolute best in every product with an Apple logo. However, none of this would have been possible without the work of Dennis Ritchie.
In the early 1970s, at AT&T Bell Labs, Ritchie and colleagues developed an operating system to improve upon Multics, a popular operating system at the time. While Multics worked well, it had many problems.
At the heart of any computer is the central processing unit, or processor. The processor is responsible for executing instructions which make up computer programs. There are many different types of processors, each capable of very simple operations. Each different processor has a different set of instructions that it can perform. The human-readable notation that describes these instructions is called assembly language. When a program is coded in assembly language, it will only run on the processor for which it was written, which can pose problems for those who want to run their code on multiple computers. Additionally, writing complex programs in assembly language is tedious.
The authors of Multics used assembly language for two specific computers to write their operating system. This meant that, to run Multics on a different brand of computer, the whole program had to be translated into a new assembly language—a technique known as porting. A program which does not need to be entirely rewritten to run on a different computer is said to be portable. Because Multics was written in assembly language, it was not portable.
Ritchie and colleagues wanted to address some of the problems with Multics. One of the main issues was that it was not portable. They tackled the problem head on. In the late ‘60s and early ‘70s, the team wrote the first version of Unix for the computers they had available. For this small project, they used assembly language. In the mid ‘70s, however, they realized they might want to port Unix to other architectures.
While Unix development was going, Dennis Ritchie was working on developing his own programming language, which would be almost as powerful as assembly language, but much simpler to use. Ritchie called his language “C.” Ritchie’s language could be automatically translated to assembly language for any computer, meaning that programs written in C could now be run on any computer. When Ritchie and colleagues realized that they would need to port the Unix system to other CPU architectures, they rewrote the entire system in Ritchie’s C programming language.
C soon became the most popular programming language around. Unix also became wildly popular, and influenced many systems which dominate the market today. As Ritchie described the projects: “C is quirky, flawed, and an enormous success.” And, “Unix is simple, it just takes a genius to understand its simplicity.”
There is C code running on just about every personal computer, server, or embedded computer in the world. C powers your laptop, your washing machine, and the traffic lights on your street computer. C has also influenced many popular programming languages and made software design easier and more accessible.
Unix was popular for many years before dying out. During its time, it led to one of the first operating system design standards. Just about every operating system not written by Microsoft is compliant with this standard to some degree. Additionally, Unix influenced the Mac operating system and Linux, which powers much of the internet. Other operating systems not directly influenced by Unix were written in C.
It’s difficult to juxtapose the roles of Dennis Ritchie and Steve Jobs in the technology industry. One effectively founded it, and the other took it and made it sexy; both are important in their own right. While Steve Jobs’ death stirred a global day of mourning, Ritchie’s was somewhat more subdued. However, when people refer to Jobs, Woz, Zuckerberg, and Gates standing on the shoulders of giants, one of the giants they’re referring to is Dennis Ritchie. In the words of this demigod, “Goodbye, world!”