Evolvotron is an interactive "generative art" application to evolve images/textures/patterns through an iterative process of random mutation and user-selection driven evolution. If you like lava lamps, and never got tired of the Mandelbrot set, this could be the software for you. It's implemented using Qt, and is multithreaded.
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.
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.
sK1 is a vector graphics editor similar to CorelDRAW, Adobe Illustrator, or Freehand. it is oriented for PostScript processing. It features CMYK colorspace support, CMYK support in Postscript, a Cairo-based engine, color management, a universal CorelDRAW (CDR/CDT/CDRX/CMX/CCX) importer, an importer for Postscript, Encapsulated Postscript, and Adobe Illustrator (PS/EPS/AI), and a modern Ttk-based (former Tile widgets) user interface.
Schnolgo is a musical composition system. It has a number of unique features, including a way of handling polyrhythmic timing which provides a flexibility one cannot easily achieve with traditional sequencing programs or sound programming environments. Currently, Schnolgo is in the form of a Python package, and its main output format for compositions written in it is MIDI.
neXtgen Povray Editor (XPE) is a graphical editor for Povray based on wxWidgets library. It looks like a modern code editor (like Kdevelop, Netbeans, or Eclipse) but is focused on Povray. It is organized to optimize work space and includes numerous features (nearly all those from Povray's Windows version and many other extra features).
Image matting tool cuts out objects in photos using an alpha-matting technique. While clear cuts can be found for all objects that are clearly separated from their environment, objects with fuzzy borders and semi-transparent areas don't have a clear outline. The tool creates an alpha channel that defines the degree to which the background shines through the foreground for every pixel. The background color can then be subtracted. The user defines a rough boundary of an object with a large brush and a high-quality segmentation is generated. Problematic areas can be edited manually.