If you're using Mac OS Mavericks, Yosemite or later you may need to update the setting to permit running Arduino IDE
- Open the, System Preferences from the Apple Menu.
- Open the, Security and Privacy control panel.
- Click on the General tab.
- Click the Lock Icon and log in
- Change Allow Apps Downloaded From to Anywhere
- Open the downloaded IDE.
- Go back to the Security preferences and change the selection back to Mac App Store and identified developers
- You only need to go through this procedure once. Mavericks will remember that it's OK to run the app.
- That's it, you're ready to start using the Arduino IDE with Adafruit's board on OSX!