grammar check
Grammar check programs are far from perfect, but can be very useful, if used properly, and I wouldn't be without one. Bad grammar and punctuation can cause rejection. Quickly.
It all depends on the Linux program you're running. WordPerfect runs on some Linux, and so does Word.
Personally, I think the best Linux OS out there right now is Xandros. The pro version costs $129, if I remember correctly, and it runs crossover office, so you can use Word.
But the best idea is not to depend on a grammar check program. Grammar check programs are most useful to those who don't need them, and horrible for those who depend on them.
Far better is to sit down and learn the rules yourself. A writer who doesn't know grammar is like a carpenter who doesn't know how to use a hammer.
Coomas aren't that complicated, and there's no excuse for not learning how to use them properly. Pick up a couple of good grammar and style books, then sit down and study them until you don't need the very limited help a grammar check can give in this area.
Better yet, go buy a seventh grade English book. It will contain everything a fiction writer needs to know about grammar and punctuation, written in a way seventh graders can understand. It really does make the task easier.