I've created this pixel editor because of the lack of smooth pixel editors inside the browser. All current implementations lack of speed and just feel clunky and slow. I've created a whole low-level pixel matrix framework from scratch for this, offering incredible speed, a undo/redo state machine and various basic transformation methods. This allows you to work on images even larger than 8000px á 8000px with very low memory consummation.
Code related pull requests are very welcome, but please make sure they match the existing code style.