If I see something I like in another application, and create something similar from the ground up in a commercial product, could I get sued over it? Of course it would be styled to look differently, however most of the functionality would be the same since the functionality is what I liked about it. It also would not be the entire system, just a part of one.I live in the US.
Can I get sued over duplicating another program's UI?
copyright
From everything anyone (including lawyers) have told me, you can get sued for anything.  The real question is whether or not you will, and whether or not they'll win.One lawyer told me, if anyone thinks you're big enough to take a run at, then that means you're successful.  In other words, suing someone is a big undertaking.  It has to be worth someone's time and money.That doesn't mean you won't get a strongly worded cease and desist letter.(Of course, IANAL).Assuming you didn't directly copy any code or screenshots or whatever, then you're probably not breaking copyright rules.  Patents, on the other hand, are overly broad, and if someone big enough to sue doesn't like you, they likely have a patent that covers anything you might be writing.Further reading: it would be worth looking at the look and feel part of this case.