Tux Paint is a simple and entertaining drawing program geared towards young children. It has a simple interface, sound effects, and a cartoon character (Tux, the Linux penguin). Along with drawing brush strokes, lines and shapes, you can also enter text and place "rubber stamp" (or "sticker") images on the picture. Tux Paint is extensible, and could be useful in an educational environment (such as a grammar, elementary, or grade school). It's portable across numerous platforms, and runs well even on slower systems like the Pentium 133MHz.
Zina is a graphical interface to your MP3 collection, a personal jukebox, a Podcaster, and an MP3 streamer. It includes an optional Flash player, a tag editor, and can search the Web for album art and song lyrics. It can run alone, be embedded into an existing Web site, or be used as a module in Drupal, Joomla, and Wordpress.
MuseScore lets you notate and compose music easily with your keyboard, your mouse, or a MIDI keyboard. You can print beautifully engraved sheet music or export it as PDF or PNG. You can play your score, transpose it, and save it as audio or MIDI file. MuseScore also supports MusicXML to let you share your composition with other scorewriters. MuseScore is often advertised as a cost effective alternative for Sibelius and Finale.
gmusicbrowser is a jukebox designed with large music libraries of over 10,000 MP3, Ogg, m4a, FLAC, and MPC files in mind. It has easy access to related songs (same artist, album, or title) and supports multiple genres per song, ratings, and labels. It has extensive filtering capabilities, customizable random modes, customizable window layouts, mass-tagging, and more.
Shape Collage is an automatic photo collage maker that lets you create picture collages in less than a minute with just a few mouse clicks. Shape Collage creates collages using an intelligent machine learning algorithm that automatically places the photos in the collage and can arrange the photos to form different shapes. You can even save the collage as an Adobe Photoshop PSD file, and edit the collage afterwards in Photoshop or GIMP.