[pjmlp]

Commercial Smalltalks for Windows are as flexible as Win32.

http://www.cincomsmalltalk.com/main/

This was the path they were on when Java happened.

[badsectoracula]

There is also Dolphin Smalltalk[0] which is an open source Smalltalk with native Win32 UI support.

[0] https://github.com/dolphinsmalltalk

[pjmlp]

Yes that was another one.

I was using Smalltalk/V for Windows 3.x back in the day, as part of some university project assignments.