TextEdit.app support HTML 5, CSS, RTF, RTFD, TXT and can be used directly as a Code Editor. It also outputs Word 97, if I'm not mistaken. Voice Dictation included. Includes ODF support as well. http://support.apple.com/kb/HT2523 It's been evolving over the years and even in it's NeXTSTEP/Openstep period did a lot more than just TXT files. RTF/RTFD, has been their from the beginning.