Mitch Kapor's Weblog: Design Notes "A little more info about our approach:
Chandler will represent chunks of information as items, much as Agenda did. An item may consist of an email, an appointment, a contact. It can also be a document. An item can be thought of us having a body and a set of attributes (or meta-data).
Views are formed (logically) by specifying a query and running that query against the repository of all items. As in Agenda, an item can appear in more than one view. This is the underlying mechanism by which we will do the equivalent of "virtual folders".
Views can be of a single item type, e.g., email, or than can be of mixed types, e.g., all items relating to a single subject, regardless of whether they are emails, attachments, contacts, or appointments.
Every item in the system will have a unique URI, so it is referenceable, both from the user's own machine and remotely.
Items can be linked in arbitrary ways as well.
Whereas Agenda was limited to a single hierarchy of categories (equivalent to attributes), in Chandler we are using an RDF-compliant schema as the backbone. It will come with a basic schema for PIM's and it will be extensible, although we are still thinking about how extensible it will be, e.g., in terms of interoperability between different schemas."
(Agenda lives... sort of.)