I don't recall the 37signals people ever complaining. There are oodles of Basecamp competitors out there, and I honestly don't think they mind the competition/copycats.
They are really very humble about competition, in general.
They are really very humble about competition, in general.
http://www.37signals.com/svn/posts/575-but-theres-only-so-ma...
Although I'd still come back and say there's only so many ways to do chat . . .
I really don't think they care if someone copies the functionality of one of their products, but I think they care when someone copies their words and design (CSS and images, in this case). Two completely different things.