Smalltalk over the years

Via Lambda the Ultimate comes a reference to a talk given by Dan Ingalls on Smalltalk in 2001:

The nice thing about a language that takes hold is that you can work with it again and again. In 30 years we have built Smalltalk systems with quite different constraints. This talk will examine a few of these, and show how tricks of the trade can be applied to enhance one aspect or another and, frequently, to make real progress.

There are video feeds of the talk - check it out.