Also, with [our product], we were going from a 16 to a 32 bit environment.

Unfortunately, I only know a few people who use Netscape.

16 to 32 still coulda used the same code, give or take, and definitely coulda used the same db schema plus additions/revisions. Though I don't agree with Joel 100%, he's got some great points in that piece. There's often a reason you've got wacky, "So we make this id negative..." bits that nearly justify the kludges. I don't judge. ;^)

That people don't use Netscape is his point. If there's any competition and you throw your lessons (saved in the code) out the door, well, you're asking for it. Everyone loves to rewrite. Few know refactoring is almost always smarter.