GIMP is a free and open source graphics editor used primarily for image retouching, editing, free form drawing, resizing cropping and making photo collages, it can also be used to convert the file types of pictures.
It has a huge range of colors to choose from and many ways to select them including palettes, color choosers and an eyedropper tool to select a color on your canvas, there is also a water color selector, CMYK selector and a color wheel selector. GIMP has native support for indexed color and RGB color spaces.
GIMP has many tools for image editing including paint brush, pencil, airbrush, eraser, and gives you the tools to create or blend pixels so that you may create your own. GIMP has approximately 150 standard effects and filters, it can be run in multiple or single window mode. Other features include a clone tool which can bused to copy pixels using a brush, a smudge tool, a dodge and burn tool which can be used to make pixels lighter or darker, a perspective clone tool to be used for distance changes, and a healing brush which can copy pixels from an area and correct tone and color.
GIMP supports importing and exporting with a huge amount of different file formats such as BMP, JPEG, PNG, and GIF, it can also import Adobe PDF documents and raw image formats used by digital cameras.
Because GIMP is open source there are several variants available to fit the needs of the user, including CinePaint, GIMP classic, GIMP portable, GimPhoto and GIMPshop.
With a plug-in it can also be used to create animations in different formats the most popular being GIF and AVI.
GIMP is an excellent free graphic editor and perfect for those who want a photo and image editor without having to pay for it.