CollectionKit provides a common storage facility for records with properties,
such as contact information, playlist, bookmark, etc.
These records have defined structure (property-value relationship) 
which can be handled better than general property list.
But values of these properties are too flexible to be stored in database,
for example, a contact information may have multiple home phone numbers.
Records can be grouped and groups can have groups inside.
AddressBook framework from Apple provides a good mechanism of handling 
these kind of records and Addresses for GNUstep implements the same interface.
CollectionKit aims to provide a general storage facility based on 
Addresses for GNUstep so that other applications and frameworks 
can easily handle their information in the same manner.
CollectionKit provide very little predefined properties.
Therefore, a framework on top of CollectionKit is needed
if the information is intended to be shared by many applications.

WWW: http://www.etoile-project.org/