Vivek Haldar has an interesting essay on How Unix Won and it why it may now be entering its end phase. From a technical standpoint, the main reason Unix fared so well is that it was written by programmers for programmers. After AT&T pulled out of the Multics project, Ken, DMR, and the others who would go on to build Unix were missing the interactive, programmer-centric environment they’d been used to so the Skunk Works project that later became Unix was born. Programmers everywhere embraced it as a comfortable and productive environment and shepherded it into their companies.
The political reason Unix became preeminent was that, being a monopoly, AT&T was prohibited from selling anything that wasn’t “telephone service” so they basically gave Unix away for the price of the media. Haldar reports that for tax purposes AT&T reported Unix as industrial waste. I hadn’t heard that before but you have to love the irony.
The reason for Unix’s impending eclipse, Haldar says, is a change in hardware capabilities. While it used to be that the CPU was orders of magnitude faster than I/O, that has largely been reversed and server installations, where Linux reign supreme, are interested in getting the most I/O speed they can. The need to maximize I/O throughput argues against the Unix abstraction model. Haldar discusses this situation in one of his read a paper videos.
If you’re a Unix head—and if you’re using Linux or macOS, you probably are—take a look at Haldar’s post. It’s an interesting and entertaining read.