But the industry has moved to C-based and scripting languages, which is sad.
Smalltalk use has declined with the rise of Java and .NET. With my own
opinions as to why there's so little industry interest in Smalltalk, I set
out to create a Smalltalk-like language for .NET which addresses those
reasons. Basically it's C# speed/power with Smalltalk readability and
flexibility. It's called SABLE.  As in ST, you can augment existing classes,
create new control structures (methods that accept block arguments), etc.,
which raises the level of abstraction available to the programmer. This is
with no loss of runtime performance; SABLE method binding is static, but the
goal is to use interpretation make it feel dynamic during development time.

You can read the introduction here; it covers almost all of the SABLE
syntax, but barely scratches the surface of what you can do with it.
http://sable-language.com

The concept of the language works, but like Smalltalk, SABLE doesn't lend
itself to file-based development. A lot more work is needed to create GUI
tools to make the language really shine. (And if I may say so, the code
generator is amazing, producing tight highly-optimal code while inlining
inlined methods, all in a single pass, with no need for peephole
optimization.)

I'm looking to connect with an industry leader who sees the potential of
this language and can assist with completing the development.and marketing.
I'm amenable to open-sourcing the language, but I need help creating a
business model. You can learn what I'm looking for here and find my contact
information.  http://kuler.com