Can I use the RTF format?

Question

I am making a text editor and I want to support rtf text files. I want my editor to create RTF text documents and read them. I was doing research and I read that Microsoft developed the rtf format. Can I make this editor without paying any royalties or getting into legal trouble?

Answer 1

You can make the editor.

Microsoft allows use of the file format under its Open Specification Program, which states that:

"Microsoft irrevocably promises not to assert any Microsoft Necessary Claims against you for making, using, selling, offering for sale, importing or distributing any implementation to the extent it conforms to a Covered Specification (“Covered Implementation”), subject to the following. This is a personal promise directly from Microsoft to you, and you acknowledge as a condition of benefiting from it that no Microsoft rights are received from suppliers, distributors, or otherwise in connection with this promise." (quoted from here)

Among the covered specifications are "Other Office File Formats", among which are RTF (document found here).

You do not need to notify Microsoft for use of these formats.