The Project PDA aims to build a real Personal Digital Assistant.
Data Collector: Collection of API Implementations to connect to several (Web-)Services and access data there
Blackbox: Entity Storage. Stores XML objects like tasks, notes etc.
PADD: Personal Access and Data Display. Named after the Star Trek Pads, it implements the GUI (or User Experience) facing the user. Can be a desktop app, web app or smartphone app. Whatever is next to the user.