PhoneGap is an open source framework that allows developers to build mobile apps using standard web technologies like HTML, CSS, and JavaScript. It allows access to native device functions like the camera from within a webview. The framework has gone through several phases of development to improve its architecture and usability. Initially it had separate codebases for each platform, but it evolved to use a single JavaScript layer across platforms. Over time, the community grew but the framework also became more complex. Later phases focused on simplifying the development process and improving documentation and consistency across platforms.