Delaboratory is a color correction utility for digital images.  It features:

  - Floating point precision (not 8-bit like Gimp, not 16-bit like most raw
    processors)
  - Native support for multiple colorspaces (sRGB, ProPhoto RGB, LAB, CMYK,
    LCH, HSL, HSV, BW)
  - Non-destructive editing (adjustment layers)
  - KISS design, realtime preview
  - basic operations: CMYK curves, CMYK levels, RGB curves, RGB levels,
    white balance in LAB, saturation in LAB, LAB curves, BW curve, HSV
    equalizer, LCH equalizer, recover shadows/highlights, vignette, local
    contrast, LAB/BW/RGB/CMYK gradients
  - expert operations: levels, curves, equalizer, exposure, saturation,
    white balance, fill, tone, local contrast, auto_dodge/auto_burn, sharpen,
    vignette, gradient, gaussian blur, recover highlights, recover shadows,
    channel mixer, high pass, c2g, copy
  - many blend modes (multiply, screen, overlay, inverted overlay, dodge,
    burn, add, grain extract, grain merge, sub, difference, darken, lighten),
    color/luminosity blending for RGB and CMYK
  - RAW support (via dcraw), up to 5 color samplers, histograms and color
    matrices, etc.

WWW: http://code.google.com/p/delaboratory/