Adobe Photoshop is a commercial bitmap and image manipulational program developed and published by Adobe Systems. It is the current and primary market leader in this field. Though it is the best, it is also one of the most expensive programs to buy. Luckily, there are quite a few free alternatives to Photoshop.
GIMP is a freely distributed program for such tasks as photo retouching, image composition and image authoring.It can be used as a simple paint program, an expert quality photo retouching program, an online batch processing system, a mass production image renderer, an image format converter, etc.It is designed to be augmented with plug-ins and extensions to do just about anything. The advanced scripting interface allows everything from the simplest task to the most complex image manipulation procedures to be easily scripted.GIMP is written and developed under X11 on UNIX platforms. But basically the same code also runs on MS Windows and Mac OS X.
Paint.NET is free image and photo editing software for computers that run Windows. It features an intuitive and