Systems, clients, servers, methods, and computer-readable media of varying scope are described that maintain versions of associations between project management objects such as source cod files, bug data, development issue data, and software specifications. One aspect of the system is that the project association data is stored in a relational database. A link set data structure provides a link to objects that are to be associated together. A link content data structure describes an individual project management object that is linked with other objects in the link set. As a software development project progresses through its life cycle, changes to the associations occur. The changes are captured and stored in the database. Previous versions of the associations are maintained in the project database, thereby allowing a user to query for the state of the project associations as they existed at any particular point in time.