4Pane is a four pane detailed-list file manager for Linux. It is designed to be fully-featured without bloat, and aims for speed rather than visual effects. In addition to standard file manager things, it offers multiple undo and redo of most operations (including deletions), archive management including 'virtual browsing' inside archives, multiple renaming/duplication of files, a terminal emulator, and user-defined tools.
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.
Allin1 is a little dock applet for FluxBox and similar window managers. It monitors CPU load with a moving graph, memory and swap usage with histograms, battery and power status with histogram and icons, ethernet/PPP interfaces with icons and histograms (linear or logaritmic), filesystem space, and Seti@home progress.
GCompris is an educational software suite with numerous activities for children aged 2 to 10. Some of the activities are game-orientated, but nonetheless still educational. These include computer discovery (keyboard, mouse, different mouse gestures), algebra (table memory, enumeration, double entry table, mirror image), science (the canal lock, the water cycle, the submarine, electric simulation), geography (place the country on the map), games (chess, memory, connect 4, oware, sudoku), reading practice, and others (learn to tell time, puzzles of famous paintings, vector drawing, cartoon making, etc.). It currently offers in excess of 100 activities, and more are being developed.
KBioritmi is a biorhythm generator for KDE. It includes a Kicker applet that shows biorhythm graphs for seven days before and after the current date, a standalone application that can show the biorhythm of a selected date and export it in CSV format, and a Coupler, which can be used to couple your biorhythms with those of another person such as your partner.