Both from my own experience and from a number of other reviews I've read, Daedelus sems to be the least bad of any software available, and it's available in both mac and IBM formats. It has invention heuristics, revision guide questions, and network collaorative editing systems (not much use if you've only got 2 computers, but there it is.) I have their address at work--I'll send it. Beware of idiot grammar-handbook-in-a-box programs. But I don't need to tell you that. Style checkers are also popular but they only work for people who already kno what they're doing. Much of their advice is unhelpful and some is absolutely wrong. But since students oftem meet them, some part of me says that they should be exposed to them when there's someone around to start a discussion of what's right and what's wrong with the specific pieces of advice they throw up. (No pun intended but maybe there should have been.) They could be great group conversation starters. Grammatick IV is the least bad I've seen. It's built into Word Perfect 6.