Nine years ago, when I was looking for a decent word processor (now that’s an old word, almost as obsolete as typewriter) for OS X I had a list of requirements...
… It had to use an open file format. Practically that means RTF, RTFD or OpenOffice. I cannot abide yet another file format that will strand my data. That ruled out Mellel and, sadly, AbiWord. I don't care if it's the second coming of WordPerfect, it has a stupid proprietary file format. That also rules out Pages and AppleWorks...
I wanted a Mac native OpenDocument compatible word processor, but that didn’t happen (remember when the EU was going to make OpendDocument work?). So I settled, for a time, on RTF. In theory. In practice I didn’t do much wordprocessing on my Macs, I did most of my writing in Mail.app, MarsEdit and Google Docs. On Wintel I used Word.
I’m not using Wintel these days, so I was looking for something other than plain text for my Mac document work. Pages is an act of desperation, and until recently Word for Mac was a lousy product, so I started using TextEdit as a document editor because its default file format is RTF.
That’s how, rather late to the game, I realized that nothing on my iPhone would work with RTF. Google Drive will display RTF contents, and convert RTF to Google Doc, but since none of my iPhone apps supported RTF I couldn’t use an app extension to open those files.
So I started asking what was up with RTF. The short answer is that RTF died - sometime between 2006 and 2012. I’ve been unable to find an obituary — it simply passed from the scene. RTF only lives on in TextEdit because it’s been baked into OS X since time immemorial — but not iOS. (Nisus Writer still uses RTF as a native file format. Might be time to give that up.)
Sheesh. Shouldn’t there at least have been a eulogy?
I guess .docx is our de facto native document file format; the heir to the dreams of RTF and OpenDocument and many before 
Meanwhile geeks are using plaintext and markdown.
This is really not what we expected...
- fn -
 If you create a new document in TextEdit, then hit cmd-opt-s, you can specify docx and save. TextEdit will then stick with .docx. There doesn’t seem to be a way in Yosemite, secret or public, to make TextEdit use .docx as a the new document format.
- Gordon's Notes: Word file formats: the Nisus achievement and a gentle wish for .DOC (.doc sort of died I guess, in favor of .docx. My comment on iPhoto is poignant given what Apple did to iPhoto and Aperture.) 2/2008
- Gordon's Tech: An RTF surprise: 850 KB to 40 MB 10/2007
- Gordon's Tech: Nisus Writer Professional: the undocumented but critical improvement 4/2009 - late fix to to the image compression problem
- Gordon's Tech: Nisus Writer Express: My Review 4/2006
- Gordon's Tech: Nisus Writer Pro, OpenOffice and Rosetta - why I bought Pages.app 9/2011 - shortly after this Pages stunk.
- Gordon’s Tech: Spotlight can now index OpenDocument files (OpenOffice, NeoOffice/J) 10/2005 (Spotlight indexing is more important than ever)
Update 12/12/2015: Scrivener uses RTF in its text editor. Might be last to do so. I suspect it’s using OS X native support. The new version of Notes.app, interestingly, uses a subset of HTML.