Sweet Home 3D
Sweet Home 3D is an interior design Java application for quickly choosing and placing furniture on a house 2D plan drawn by the end-user, with a 3D preview.
Open Computer Vision Library
The Open Computer Vision Library has > 500 algorithms, documentation and sample code for real time computer vision. Tutorial documentation is in O'Reilly Book: Learning OpenCV.
gnuplot
Famous scientific plotting package.
GNU Octave Repository
Central storage place for script and function files used with GNU Octave.