Editors with code completion

Hi again,

there are more editors with code completion. There is TextEditor, its subclass SmalltalkEditor and then there are RubTextEditor and again its subclass RubSmalltalkEditor what is the rule?

I found out that with the finder tool there is a TextEditor but most of the editors seem to be RubSmalltalkEditor. I also got the impression that a lot of the code is duplicated.

Thanks,

Lukas