PhoneGap is an open source tool that allows developers to build mobile apps using HTML, CSS, and JavaScript. It wraps the web view container to give apps access to device features like geolocation and accelerometers. While documentation is still maturing and bugs may exist, PhoneGap is free, open source, and provides a unified way for developers to build cross-platform apps without having to learn multiple native SDKs. Sample PhoneGap apps and getting started resources are available online.