# It should allow users to seamlessly use their existing Thunderbird address books and contacts
# It should not require configuration in order to be useful
# It should not change the experience for users who do not use the address book, or use a different method for managing their contacts.
# It should react instantly to user interaction, or display loading / progress widgets when processing a slower job
# It should have extensibility baked in - we should assume that add-ons might add new contact providers, or new functionality to the address book