AIMSpy is an application that parses and displays content from instant messaging systems using the local network. It is multi-threaded, uses BPF devices for network access, and includes fairly thorough support for the AIM chat protocol and rudimentary support for the Rendezvous (iChat) protocol.
ActoTracker is an application for keeping track of activities on your desktop so that you don't have to. Think of it as an app for bookmarking desktop documents and applications. It can also bookmark things that are not usually tied to a URL such as Outlook email message or Filemaker records. It can be extended to handle additional applications by writing custom AppleScript plugins. ActoTracker is somewhat inspired by the GNOME Activity Journal (Zeitgeist framework), and it tries to solve a similar kind of problem for the end user, although in a different way.
AddressBook X LDAP provides a shared addressbook on your local network, without the burden of subscriptions. It is an iSync enabled application which transfers contacts from the AddressBook to a central LDAP directory. It also provides the ability to browse and search the directory. Multiple schema mappings are available and can be customized and extended to address individual needs. Currently, ABxLDAP Person (an extension to InetOrgPerson) is fully supported, but the Mozilla Schema and the basic InetOrgPerson are in development. Support for Active Directory is included as well.
Addresses is a GNUstep address book that consists of a full-featured address book manager application, a source-code compatible replacement for Apple's AddressBook.framework (for accessing and manipulating address data programmatically), a framework of view/editor classes that make it easy to use Addresses from your own programs, and a number of tools. It is easy to use by both users and programmers and can store almost all imaginable data, including multiple phone numbers, emails, and addresses, photos, AIM/Jabber/ICQ/Yahoo IM details, and notes. It supports drag-and-drop and integrates well with GNUMail.