Ken Shirriff writes:
The first programming language for the Xerox Alto was BCPL, the language that led to C. This article shows how to write a BCPL “Hello World” program using Bravo, the first WYSIWYG text editor, and run it on the Alto simulator.
The Xerox Alto is the legendary minicomputer from 1973 that helped set the direction for personal computing. Since I’m helping restore a Xerox Alto (details), I wanted to learn more about BCPL programming. (The influential Mesa and and Smalltalk languages were developed on the Alto, but those are a topic for another post.)
Full details at Ken Shirriff’s blog.