My professional background in developing software with Smalltalk includes implementing HMIs and machine control logic. I used VisualWorks with refactoring tool Refactoring Browser as well as repository manager ENVY/Developer.
In retrospect, Smalltalk indeed gave me profound grounding in object orientation. I was very fortunate to work with this language in two large industrial projects at the beginning of my career.
Being a "pure" OO language with simple, elegant syntax and powerful IDE that eliminates the usual "Edit-Compile-Link-Run-Test-Debug" build cycle, Smalltalk enabled rapid development of both Lynx and ProCell.