Recs.
Updated
Microsoft Office bundled note-taking software. OneNote is available for Windows, Mac OS, iOS, Android, Windows Phone, and Symbian.
SpecsUpdate
Pros
Pro Comprehensive organization methods
Can have multiple 'sections/tabs' at the top like in a web browser with many notes within each 'section/tab'. Also, there can be sections within section groups infinitely. The complete hierarchy looks like this: Notebooks > Section Groups ... Section Groups > Sections > Pages > Sub-pages > Sub-pages.
Pro Supports hierarchical organization of information / notes
OneNote is designed to allow hierarchical organization of information. This is achieved with grouping into the following categories and UI elements (Notebooks, Sections, and Pages). Both Sections and Pages allow additional groupings that can be expanded / collapsed in list view.
This can be incredibly helpful for quickly taking notes and organizing them for work or personal projects.
For example, you could have a Notebook for "Cooking Recipes", with sections for "breakfast, dinner, desserts", where individual recipes would be page entries (i.e. the "Desserts" section would have pages for brownies, chocolate cheesecake etc).
Pro Strong search features let you quickly find what you're looking for
If you don't want to search through all of your notes, you can narrow it down by specifying the page, section, group, or notebook.
You're not limited to just searching through your text either. You can search for text in images, video recordings, and audio (this is off by default).
Pro Article Web Clipper available on desktop and mobile
Has a web clipper extension on Chrome and Edge that can be used for clipping whole articles and images. Web clipping of articles is also available on Chrome mobile through the "Share" option.
Pro Cross-platform
Its available Windows Mobile, Windows Store, Android, a Desktop Version, and a Web app. Apple macOS and iOS are also supported.
Pro Sharing and collaboration
You can share your notes by inviting people with an e-mail, or by giving them a direct URL. You have control over what kind of access the user has on your note (read only, edit) and can revoke it at any time.
OneNote will alert you when a chance is made on your shared note.
Pro Offers flexible encryption
Unlike most other apps, you can selectively password protect, and fully encrypt, individual documents or entire folders. This is especially important to many people with data stored in the cloud. As of early this year, even the free version supports encryption. Microsoft has also enhanced their internal security methods for storing data on OneDrive (where OneNote performs sync), which makes it more secure than most of their competitors (including Evernote).
Pro Import and link calendar events and tasks in Outlook
This is great for taking meeting minutes. You can import all the meeting details, including a checklist of attendees and a link back to the original event in your Outlook calendar. You can tag all the actions coming out of a meeting and you can create linked tasks from them in Outlook. Much quicker and more effective than writing meeting minutes the traditional way.
Cons
Con Not open-source
This application is proprietary, and thus cannot be modified or freely distributed.
Con The added flexibility means your notes may feel cluttered
Since you can place elements anywhere you'd like on your note, you have to pay attention to how you structure it. For some this added flexibility is a huge selling point, but for others it could become distracting and makes notes feel difficult to digest.
Con Sync isn't stable
Many users have reported synchronization issues. While not everyone will experience this, it can be difficult to troubleshoot, with some fixes resorting to editing registry keys in Windows when using the Windows client.
Con Text editing is weird (poor UX)
When clicking in the middle of a note, it adds something like a text-box positioned in the middle. If you move that field to the bottom right, it gets weirder. You can end-up with an empty note, having an empty text-box 1km to the bottom-right of it.
Con Platform dependent
The newer versions for Windows and Mac are converging, using the Windows style layout (with a more more consistent and usable UI).
The original OneNote for Mac for example is very different from OneNote for Windows. Because Microsoft has a vested interest in making sure the Windows version is superior, the Mac version tends to lag behind in terms of functionality. Tutorials and other forms of documentation available online generally apply only to the Windows version, which implies non-Windows versions are undocumented.
Even worse, because the documentation rarely, if ever, indicates it only applies to Windows, it's easy to waste hours trying to make non-existent features work. As such, the documentation is "negative documentation" (i.e. worse than no documentation at all).
Con You cannot use local OneNote files with the version of OneNote that is included with Windows
There is a difference between the OneNote that is included with Windows 10 and the OneNote that comes with Microsoft Office. The version included with Windows cannot use local OneNote files and requires you to be online to access your notes.
See here for this and other differences.
Recommendations
Comments
Flagged Pros + Cons
Pro It's free on all platforms with free cloud sync
OneNote is available for free as a web app as well as natively on iOS, Android, OS X, and Windows. You can also use OneNote for free on as many devices as you want.
Con Copy/paste of text into other apps is pasted as image rather than text
Con All files must be stored in the cloud
OneNote does not offer support for local storage.