Can one be sued for copying the "look and feel"?

Hypothetically, can Microsoft sue OpenOffice for copying the "look and feel", "command and menu structure", "copyright infringement" and the other similarities in the User Interface?

You can be sued for anything in the U.S.

However, the US Supreme Court settled this issue in 1996 in the case of Lotus Dev. Corp. v. Borland Int'l, Inc. Borland copied the complete Lotus 1-2-3 menu structure in their Quatro Pro software product. The Supreme Court ruled in Borland's favor.

Borland vs Lotus So unless you are infringing on a patent, trademark, or design patent- you can copy the look and feel of another program.

Obviously people can sue for about anything, determining if they will prevail is another matter.

As to "look and feel", if it is part of the key branding of the product or service and has been registered with the Patent and Trademark office, then they will most likely win.

Consider McDonald's golden arches, clearly a part of the look and feel of a McDonalds hamburger stand, if you open a hamburger stand with your name and two yellow arches, you can virtually be guaranteed that McDonalds will win against you.

With software you will find that in addition to trademark elements there are numerous patents that have been filed with respect to interface design which may or may not be valid, but which you could run afoul of.

Since you are asking this in OnStartups, I am guessing that you have an idea for a product or a product in the works which you are concerned may put your company at risk in this area. Given that context, there are a few things you should consider:

• How closely does the new product mimic the old? If it is so close that a user might be confused then you might be at risk. The purpose of these lawsuits is to protect the "image" created by the originator. I think this is the difference between the Lotus v Borland suit and the McDonalds example above. Borland copied the functional flow of the menuing structure which was not specifically part of Lotus's "image".
• Does the originating company actually own that look and feel. I believe one of the big questions being kicked around in the old Apple v Microsoft suit was whether Apple could sue for something that XEROX PARC had actually created (and iirc, gave to the public domain)
• Lastly, but possibly most importantly, does the originating company have enough money and lawyers to kill your company in a protracted lawsuit. Even if you might have prevailed in the end, you could lose the war by the lawsuit bankrupting your startup before you ever get that far. Depending on the financial strength of your company, this might be the biggest reason to steer clear.

IANAL and your mileage may vary :)