Comment Patents! (Score 1) 604
If you're rewriting from scratch, make sure they don't have any patents on their product. They can't win a copyright suit unless they can prove you actually copied code. A patent suit is more squishy in that they only have to prove you stole their patented idea.
However, be cautioned, this move will cost you -a lot- as in NO INCOME until you sell product. How's that for encouragement?