1) I've spent a reasonable amount of time using 4 or 5 and dabbled in one or two.

2) Depends on the language. The transition from C++ to Java was pretty easy. Syntax and concepts were similar so quirky differences and differant libraries were challenging. Moving from c++ to Lisp was an entirely different experiance. The concepts behind the languages were not in sync.

3) Yup, I wrote a parser in Java that would have been much. much easier with a StringTokenizer. I'm sure I've done this other times, but that one really gets me.

After reading the article:

1) One thing that struck me while reading the article was that CodeBroker encouraged re-use in a way I wouldn't have intially considered. By prompting the user to write quality comments by rewarding them with help, the system may increase the reuseability of code created while useing it.

2) This is the kind of tool that I think could make a lot of progress out in the wild. If it's installation could be made fairly light-weight selling some Java programmers on it would be pretty easy. Extensions and modifications to the system in the wild (if permitted) would indicate what programmers found useful and wanted more of, or better.