This is an addon for openFrameworks (http://openframeworks.cc) that based on the shaders available in Brad Larson's iOS GPUImage library (https://github.com/BradLarson/GPUImage) as well as a number of effects from the ofxCv addon I've moved into shaders for improved performance.
There's a real-time Difference of Gaussian filter that makes you look like a cartoon, a Kuwahara Filter for the kids, Perlin Pixelization for the grownups, Motion Tracking for the paranoid, and a creepy Bilateral filter for the self-conscious teen in all of us. You might also enjoy the stained glass-looking Voronoi implementation, the retro CGA Color Space filter, or the utilitarian Harris Corner Detection.
Here's a few of the filters in action:
Nothing, really.