Microsoft Paint - Paint (formerly Paintbrush) is a simple, ultra-basic graphics painting program that is included...
Online Image Editor - Online editor for images and animated gifs with multiple effects and tools
MyPaint - MyPaint is a fast, distraction-free, and easy painting tool for digital artists.
Pixelitor - Pixelitor is a cross-platform raster graphics editor written in Java.
GIMP - GIMP is a multiplatform photo manipulation tool.
RealWorld Photos - RealWorld Photos is an free portable photo editor for Windows.