Gaby is a small personal database manager using GTK+ and GNOME (if available) for its GUI. It was designed to provide straight-forward access to the types of databases a casual user would normally use, while keeping the ability to easily create databases for other needs. It was designed with extensibility in mind and relies heavily on plug-ins.
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.
ToutDoux is a project manager for GNOME. The approach of data manipulation is abstract (database free). It's extensible with plugins. Most tasks are and will be subcontracted with commandline frontends. The file format is XML (including a schema, plugins parameters, and datatables).
Copper is the feature-wise Linux port of the Windows-only software Golden32 by Benthic. It allows developers to view data in a table format rather than in SQLplus, and lets you do select, insert, update, delete, commit, and rollback. It supports Oracle and MySql, and features a tabbed view to manager your queries, syntax highlighting, right-click updates, and a table/column browser.
SyncEvolution synchronizes personal information management (PIM) data like contacts, calenders, tasks, and memos via the SyncML information synchronization standard. SyncEvolution compiled for GNOME's Evolution supports all of these data items. Compiled for Nokia 770/N800/N810 Internet Tablets, Mac OS X, and the iPhone, it supports synchronizing the system address book. The command line tool 'syncevolution' (compiled separately for each of these platforms) executes the synchronization.
DWI, Data With Interaction, is an Object-to-Relational Mapping (ORM)-based RAD (Rapid Application Development) system for rapidly creating data-driven desktop GUI applications. It maps SQL tables into several object systems, including QOF, GLib GObjects, and GTK/GNOME. It can be used with the Glade GUI designer. It supports multiple databases through ODBC and libdbi.
The chemical-mime-data package is a collection of data files to add support for various chemical MIME types on Linux/Unix desktops, such as KDE and GNOME. Chemical MIME types were proposed in 1995, though it seems they have never been registered with IANA. But they are widely used, and the project's aim is to support these important but unofficial MIME types. Initial data was taken from "The Chemical MIME Home Page" of Henry Rzepa.