Milton is an Open Source painting program that's easy to use and allows you to "Just Paint."There are no pixels; you can paint with (almost) infinite detail. It feels raster-based, but it works with vectors.The application is under 2 megabytes and simple to use. There are still quite a few options including backgrounds, eraser, brush options, layers, opacity and more. There is no save button to worry about as your work is persistent and you can undo at any time.