Textutil handles a couple of apple-specific file formats (rtfd, webarchive) that do an embrace-and-extend on open(ish) standards.
(Annoyingly it doesn't provide a way to get at the guts of Apple's own Pages files. Which sucks because the only tools for transcoding Pages are Pages itself, and icloud.com.)
(Annoyingly it doesn't provide a way to get at the guts of Apple's own Pages files. Which sucks because the only tools for transcoding Pages are Pages itself, and icloud.com.)