GCstar is a free open source application for managing your collections. (GPL)

Griffith is a media collection manager application. Adding items to the collection is as quick and easy as typing the film title and selecting a supported source. (GPL)

Krecipes is a COOKING application meant to be the KDE Recipe Tool. It manages a recipe database with an easy to use interface. (GPL)

Tellico is a KDE application for organizing your collections. A simple and intuitive interface shows cover images, groupings, and any detail you want. (GPL)