HaRET stands for Handheld Reverse Engineering Tool. It is a Linux bootloader developed at the XDA-developers forum that boots from within Windows Mobile and allows you to run Google Android OS on it.

Some of the features that you can use in Android OS running on Windows Mobile include:

- TouchScreen
- Onscreen keyboard
- SMS
- Radio
- Make Audio calls
- Adjust Backlight and Keypad light
- Webkit browser
- Storage card
- Camera
- Data connection
- Install Android (APK) applications
- Adjust screen brightness
- Google Sync, Google maps
- Screen rotation and orientation

Learn how to install Android on Windows Mobile here.