The document provides an overview of several mobile operating systems including Symbian OS, Android, iPhone OS, Windows Mobile, and Palm OS. It describes key features of each such as supported programming languages, software development kits, user interface elements, and market share. Symbian OS is an open source OS designed for battery powered devices with low memory. Android is an open source OS based on Linux that uses Java and supports voice input. iPhone OS has a multi-touch interface and is Apple's proprietary OS for the iPhone, iPod Touch, and iPad. Windows Mobile supports both touchscreens and keyboards and allows third party development. Palm OS was designed for ease of use on touchscreens.