Gorillized's Outline was developed to be a OneNote alternative before OneNote hit the Macintosh last year. It was originally designed as a mere reader of OneNote files on iPad, but turned into a full-blown editor and has since added Mac support too. That makes it an interesting alternative to both OneNote for people who don't want to part of Microsoft's ecosystem, and to Evernote for people who want something different.
Full story from the iMore Blog...