Freeware - Raster graphics editor

Gimp

reliable site.

OpenSource

The popular lightweight graphics editor that competes with Photoshop, requires GTK RunTime.

GimpShop

reliable site.

OpenSource

The popular lightweight graphics editor that competes with Photoshop, requires GTK RunTime. Version made specially for those who are used to Photoshop.

Paint.NET

reliable site.

OpenSource

Simple but powerful and handy graphics editor very similar to Photoshop.
supported formats: BMP, IPEG, PNG, TIF, GIF, TGA and to the native format of PDN;
key features: work with layers, apply effects, work with scanner and camera, red eye correction, scaling from 1% to 3200%.
the program itself is less than 3 Mb, but it is necessary .NET Framework (20 Mb) (which is free skacati from Microsoft).'

Pinta

Easy, but functional editor.
Those who first encountered Paint.NET must've struck close to the Photoshop functionality and extremely small size.
the Authors Pinta not finding Paint.NET decided to make a cross-platform graphics editor, similar to Paint.NET — Leki and functional.

UFRaw

OpenSource

Utility and extension of GIMP for processing raw files RAW. The program is based on the source codes of the dcraw thanks to which supports a large number of RAW formats from different manufacturers of digital cameras.

Krita

OpenSource

Full-featured raster graphics editor with open source.

1. support for touch screens,
2. Layers,
3. retouching tools,
4. frame-by-frame animation,
5. A customizable pop-up menu,
6. the possibility of seamless pasting of textures,
7. Brushes,
8. sensitivity to pressure, tilt ...
9. Customizable hotkeys.