About GIMP :

The GNU Image Manipulation Program, or GIMP, is a raster graphics editor application with some support for vector graphics. GIMP is used to process digital graphics and photographs. Typical uses include creating graphics and logos, resizing and cropping photos, altering colors, combining multiple images, removing unwanted image features, and converting between different image formats. GIMP can also be used to create basic animated images in GIF format. It is often used as a free software replacement for Adobe Photoshop, the most widely used bitmap editor in the printing and graphics industries.

GIMP Features

• Painting
  • Full suite of painting tools including Brush, Pencil, Airbrush, Clone, etc.
  • Sub-pixel sampling for all paint tools for high quality anti-aliasing
  • Extremely powerful gradient editor and blend tool
  • Supports custom brushes and patterns
• System
  • Tile based memory management so image size is limited only by available disk space
  • Virtually unlimited number of images open at one time
• Advanced Manipulation
  • Full alpha channel support
  • Layers and channels
  • Multiple Undo/Redo (limited only by diskspace)
  • Editable text layers
  • Transformation tools including rotate, scale, shear and flip
  • Selection tools including rectangle, ellipse, free, fuzzy and intelligent
  • Advanced path tool doing bezier and polygonal selections.
  • Transformable paths, transformable selections.
  • Quickmask to paint a selection.
• Extensible
  • A Procedural Database for calling internal GIMP functions from external programs as in Script-fu
  • Advanced scripting capabilities (Scheme, Python, Perl)
  • Plug-ins which allow for the easy addition of new file formats and new effect filters
  • Over 100 plug-ins already available
• Animation
  • Load and save animations in a convenient frame-as-layer format
  • MNG support
  • Frame Navigator (in GAP, the GIMP Animation Package)
  • Onion Skin (in GAP, the GIMP Animation Package)
  • Bluebox (in GAP, the GIMP Animation Package)
• File Handling
  • File formats supported include bmp, gif, jpeg, mng, pcx, pdf, png, ps, psd, svg, tiff, tga, xpm, and many others
  • Load, display, convert, save to many file formats
  • SVG path import/export