Pinot is a D-Bus service that crawls, indexes your documents, and monitors them for changes. It is also a GTK-based user interface that enables you to query the index built by the service or your favorite Web engine, and display and analyze the results. It makes full use of advanced indexing and search facilities offered by Xapian, features language detection, dynamic document summaries, easy labelling of documents, and internal support for common file types. The D-Bus interface allows easy integration with other applications.
Smuxi is an irssi-inspired, flexible, user-friendly, and cross-platform IRC client for sophisticated users. Smuxi is based on the client-server model: The core application (engine) can be placed onto a server which is connected to the Internet around-the-clock; one or more frontends then connect to the core. This allows the connection to IRC to be kept up even when all frontends have been closed. The combination of screen and irssi served as the example for this architecture. Smuxi also supports the regular single application mode. This behaves like a typical IRC client; it doesn't need separate core management and utilizes a local engine that is used by the local frontend client.
Alexandria is a GNOME application to help manage a book collection. It retrieves book information (including cover pictures) from several online libraries, allows you to search for a book (either by EAN/ISBN, title, authors, or keyword), can import and export data into ONIX, Tellico, and EAN/ISBN-list formats, generates Web pages from your libraries, allows marking your books as loaned, saves data using the YAML format, features an HIG-compliant user interface, shows books in different views that can be filtered or sorted, and handles book rating and notes.