Paint.NET

Paint.NET is a free image and photo manipulation software for Windows 2000, XP, Vista, or Server 2003. Paint.NET started development at Washington State University with additional help from Microsoft, and continues to be updated and maintained by some of the alumni that originally worked on it. Paint.NET features layers, painting and drawing tools, special effects, unlimited undo history, and levels adjustments. Paint.NET is completely free, and the source code is also available for free.