Mac applications that support RTF and RTFD include Apple's TextEdit and Pages, and a third-party free program called Bean.
However, as previously stated, some of the contents, such as graphics elements, will be lost after editing when the RTFD file is subsequently re-opened in macOS.
If RTFD is converted to WebArchive on a Mac by using the "Save As" function in TextEdit, it may be opened and viewed in the web browser Safari even in Windows.
In contrast to RTF, RTFD files generally cannot be opened properly by applications on operating systems which do not recognize the bundled data.
Most applications and operating environments on Linux, like Windows, treat the bundle as a folder containing unstructured data files.