[newmana]

Smalltalk Environment - the dawn of IDEs - "Don't mode me in"

"Novices are not the only victims of modes. Experts often type commands used in one mode when they are in another, leading to undesired and distressing consequences. In many systems, typing the letter "D" can have meanings as diverse as "replace the selected character by D," "insert a D before the selected character," or "delete the selected character." How many times have you heard or said, "Oops, I was in the wrong mode"?"

https://archive.org/details/TheSmalltalkEnvironment