A collection of more or less useful Javascript utils and snippets
ZorroSVG - Put a Mask on it.
Converts transparent PNGs to SVGs and can shrink file sizes considerably. http://quasimondo.com/ZorroSVG/
Various Blurs:
Stack Blur (best quality/speed ratio): http://www.quasimondo.com/StackBlurForCanvas/StackBlurDemo.html
An explanation how the Stackblur Algorithm works can be found here: https://github.com/Quasimondo/QuasimondoJS/blob/master/blur/stackblur.pdf?raw=true
Compound Blur with variable radii: http://www.quasimondo.com/CompoundBlurForCanvas/CompoundBlurDemo.html
Superfast Blur (fastest, but not so beautiful): http://www.quasimondo.com/BoxBlurForCanvas/FastBlurDemo.html
Stack Box Blur (another fast variant): http://www.quasimondo.com/BoxBlurForCanvas/FastBlur2Demo.html
Integral Image Blur (and another fast variant): http://www.quasimondo.com/IntegralImageForCanvas/IntegralImageBlurDemo.html