What is the status of using a ribbon UI on Windows or any other platform? Is Microsoft still asserting IP rights, and is a license required?
Note that there are many questions online about this, but no answer, much less a sourced one stating Microsoft's official position. This leaves many developers in a state of uncertainty.
As of 2017:
- No documentation on MSDN anywhere mentions a license. Consider, for example, the MFC ribbon overview.
- The VC++ 2017 MFC
CMFCRibbonBarclass, the only ribbon installed with VS2017, links to the retired license in its header. This header has not changed for many years. Its documentation does not mention a license.
- The Visual Studio 2017 license does not mention the ribbon.
- The Windows 10 SDK license does not mention the ribbon (checked against 10.0.15603.137, downloaded 2017-04-11.)
- Some believe this means no-one who did not sign a license before it was retired are able to legally use a ribbon.
- A 2009 comment in a forum (not a good basis) states there are "no unusual licensing requirements".
- There has been no statement by Microsoft of a change in its attitude the the ribbon, arguably meaning that now a license is no longer available, no developers can use a ribbon.
- Microsoft uses a ribbon in its macOS Office applications, but has not indicated if other developers may use a ribbon on non-Windows platforms
- There is significant doubt if the ribbon is valid IP.
This leaves all developers who did not sign a license prior to it being retired in limbo and uncertainty, not knowing:
- If they can use the inbuilt WinAPI ribbon control on Windows 10 without a license
- If they can use a third party ribbon control on Windows without a license
- If they can use a third party ribbon control on macOS or Linux
- If they can use a ribbon for an application that competes with a Microsoft application (either Office, or other.)
Please cite sources, and prefer the kind of sources you could quote if it became legally important, above sources that are a comment on a forum. I'm seeking a definitive answer, and won't mark a "it's probably ok, you'll get away with it" answer as correct.