Is there a common denominator of all Smalltalk implementations?

Question

In most languages, there is standard libraries. And this is foundation, common denominator of them. Applications can be written with guarantee of the denominator.

What's the core of Smalltalk?

Answer 1

There is actually an ANSI Standard (PDF) for Smalltalk, with which all implementations should comply. However, most of them miss compliance in some small ways. There is also the original Smalltalk 80 documentation, which again most Smalltalks comply with.