pngquant is a command-line utility for converting 24/32-bit PNG
images to paletted (8-bit) PNGs.  The conversion reduces file sizes
significantly (often as much as 70%) and preserves full alpha
transparency.  Generated images are compatible with all modern web
browsers, and have better fallback in IE6 than 24-bit PNGs.

Optional features:
OPENMP=yes|no (default: no) Enables parallelized batch jobs.

Note: OPENMP=yes builds are currently broken. If this bothers
you, please send a patch to fix it.