ABalloon for Mac

From Jim Walker's Software:

I've always been annoyed by applications that don't bother to implement balloon help (or, these days, Carbon Help), and I was flabbergasted to discover that there was no obvious way to do balloon help in PowerPlant windows. I later found that several people has posted their own solutions in the contributed classes archive at the Metrowerks web site. Here is another one, which has advantages over any others I have seen. ABalloon does not require you to write or modify any code (except to register the class), works with default buttons, and even works with nested panes.