Mac: OneNote is one of our favourite note-taking tools, but non-Windows users have always been missing OneNote's awesome note-taking capabilities. Growly Notes brings a OneNote-like interface and lots of features to the Mac—for free.
Free note-taking apps like Evernote and Zoho Notebooks are great cross-platform tools, but OneNote, even with its fairly high price tag, still has its devoted fans. For some Mac users, like myself, OneNote is a major reason to run Windows virtualisation software. Although Growly Notes lacks many of the more robust features of OneNote, it has a similar interace, is free, and runs on OS X.
You'll find a lot of the features on Growly Notes that separate OneNote from Evernote and other note-taking tools: a tabbed interface, page templates, notebook templates, the ability to add or move things around wherever you want on a page, and special visual tags within your pages. If you're a OneNote user on Windows, learning to use Growly Notes won't be that difficult.
The software also offers notes searching, password protection, audio and video files insertion, and a lot more. Although it doesn't have the convenient cloud-syncing that Evernote offers, Growly Notes does have a "shared notebook" feature that can sync notebooks to a network server, including MobileMe. Handwriting recognition, unfortunately, is also missing.
I played with the program a little bit and thought the freeware application offered a lot of impressive features. It's not as rich an experience as using OneNote, perhaps (and sometimes there were bugs like the highlighter not working for me), but it's definitely worth a look if you want OneNote-like notebooks on the Mac.