Ribbon GUI and Microsoft

There has been much controversy on ribbon style GUI and Microsoft’s patents. Nobody really seems to know whether a ribbon may be implemented in other software or not. Now it is being tested on Libreoffice so somebody clearly knows about its legality.

Has a research been made about the legality matter or are developers just confident enough that there is enough prior art which makes the ribbon unpatentable?

This could be a great opportunity for the entire open source community. Many open source software suffer from bad user experince and ribbon could make many programs more easy to use.

Quoting @Kestis: “Now it is being tested on Libreoffice so somebody clearly knows about its legality.”
How did you come to this conclusion? Are you talking of the “Muffin” / “Noteboolk toolbar”?
Quoting @Kestis: “…and ribbon could make many programs more easy to use.”
You are kidding?
My ribbon experience is mainly with Win Components, Foxit Reader, and a few occasional contacts. It’s a nightmare.

Many open source software suffer from bad user experince and ribbon could make many programs more easy to use.

That is an interesting statement. Is it a result of some reliable research? Can you share the respective document(s).

@Lupp Yes I’m talking about the Muffin/Notebook. I don’t think that it would be developed if it clearly was a patent infringement.
I use many software with ribbons in my job and they are very easy to use. It’s insane to have toolbars full of tiny buttons when you can only see the ones you need at the moment.

@gabix It’s only my own experience with many commercial software and their open source counterparts.

@Kestis: There surely is some similarity between muffin and “the ribbon”. It is, however rather superficial, and even US law on “protection of intellectual property” will not find it illegal to use a cross symbol or a little image of a printer e.g. to trigger the obvious functionality just because someone else did it in licensed software using similar icons.
The matter was discussed to some detail in the late (sigh!) libreofficeforum.org e.g.

@Kestis again: You may know that MS granted a license for the Ribbon, (not just for the look-and-feel) as a kind of an add-in for “free”, but not in connection with software directly competing with MS “products”.
Everything, including the “ribbon” itself just war on free and open competitors? “Don’t try to be better if you want to be successful. Resort to doping or advertising instead”? Why not “useful payments”?
I don’t want to fall for their line.

Well, the zoom bar in the lower right corner is probably also infringing on Microsoft’s patent on sliders.