The Android SDK ships with a number of powerful tools to help with common Android development tasks. The Android documentation is an essential reference for developers. The DDMS debugging tool, which is integrated into the Eclipse development environment, is useful for monitoring emulators and devices. The Android emulator can be used for running and debugging Android applications virtually, without the need for an actual device. There are also a number of other tools for interacting with handsets and emulators at the command-line level, as well as specialized utilities for designing Android application user interfaces and graphics, as well as packaging applications.