Building Objects

What then is a personal computer? One would hope that it would be both a medium for containing and expressing arbitrary symbolic notions, and also a collection of useful tools for manipulating these structures, with ways to add new tools to the repertoire.

Alan C. Kay, "A Personal Computer for Children of All Ages"

Smalltalk is both a very personal and a very live system. This affected the experience of using, building, and sharing objects built in the system, which were all done in a way very different from the edit-compile-assemble-link-run workflow associated with COBOL and later languages.

As an aside, I'm mostly using "Smalltalk" here to mean "Smalltalk-80 and later things that derived from it without changing the experience much." Anything that looks and feels "quite a lot like" a Smalltalk environment, such as Pharo or Squeak, is included. Things that involve a clearly more traditional workflow, like Java or Objective-C, are...