Evernote is a suite of software and services used for note-taking and archiving. Evernote software is available on a variety of different platforms and user data is stored locally in a proprietary format. Evernote services provide a means to back up / synchronize data across devices.
- Notes don't need to be named in order to be stored
- Categorization via tags and "notebooks"
- Full-text search, faceted search, and seach-within-images via OCR
- Note context like date and location is stored automatically
- Inline images within notes
- The ability to embed any kind of file within a note
- Easy note-capture via the app, website, bookmarklets, browser extensions, or via email
A variety of apps and services integrate with Evernote including:
- Confluence, Atlassian's enterprise wiki
- Whitelines Link, an iOS app for scanning documents (also has email and Dropbox integration)
- IFTTT - see evernote blog post
Evernote data can only be exported via the desktop application and is available in either HTML or the Evernote XML format (.enex).
- "Evernote’s employees read your private notes in order to “improve machine learning”!"  
- "You cannot opt out of employees looking at your content"