Ansel is a Horde photo gallery that provides functionality for managing unlimited photo galleries, with thumbnails, paging, EXIF data, and permissions on a per-gallery basis. It also provides a number of features not normally found in Web-based photo galleries, including cropping, resizing, rotating, watermarking, and greyscale effects.
Roundcube Webmail is a browser-based, multilingual IMAP client with an application-like user interface. It provides the full functionality you expect from an email client, including MIME support, address book, and folder manipulation. High extensibility is granted by the plugin API and the user interface is fully skinnable using XHTML and CSS 2.
SyncWall is a basic wallpaper changer with a special feature, the ability to synchronize wallpaper changes between several workstations with a basic (and unsecured) client/server protocol. Each workstation must share the same pool of files, there is no FTP or Internet download. Other interesting features are simple multi-monitor support and the ability to add special effects to wallpaper.
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.
Quassel IRC is a modern, cross-platform, distributed IRC client, meaning that one or more clients can attach to and detach from a central core, much like the popular combination of screen and a text-based IRC client, but graphical. In addition to this unique feature, it aims to be a comfortable chatting program.