symTone is a dual cursor image manipulation program that allows users to easily and intuitively edit their digital photos using two mice and two cursors. symTone requires that the user plug in two extra three-button USB mice (in addition to their laptop touchpad or their desktop mouse). Mice with a scroll wheel as the middle mouse button will work fine. Only the PNG file format is currently supported.
ArahPaint4 is a textile-oriented paint program, mainly for jacquard. It is a simple paint program for raster palette images. It has good tools for drawing images in repetition, support for handling palette images (color reduction, substitution, protected, transparent colors), contour tools, layer support, unlimited undo/redo, support for drawing in aspect ratio (pixels need not be square), a two level grid, and a coordinates display. It is simple, stable, fast, and works well on large images (>8000x8000).
Arachne is program that implements Avidan and Shamir's seam carving technique for content-aware image resizing. It allows realtime, fluid image resizing using this fascinating technique. Seam carving works by removing the "boring bits" from an image, so it can change the aspect ratio of many images without changing the shape of the objects inside.
Gimp User Filter is a work-alike to Adobe's Filter Factory. It is a generic image processing plug-in that can be used to create new filters for The GIMP without having to go through the process of learning about The GIMP's SDK. Many freely available filters that have been created for Filter Factory can also be used with this plug-in.
F-Spot is a personal photo management application for the GNOME desktop. It simplifies digital photography by providing intuitive tools to help you share, touch-up, find, and organize your images. These tools include editing, color adjustments, tags, Photo CD creation, and exporting for upload.
Flowpaint is a next generation paint program that focuses on usability and power. It's cross platform and supports pressure sensitive graphics tablets. Planned features for future versions include user-editable procedural brushes, brushes created from pictures, layers with arbitrary data channels, infinite and wrapping canvas layouts, parametrized picture templates, and built-in support for downloading and sharing new brushes and templates.