Whitescape, a group dedicated to Inkscape, an open source vector graphics editor, with capabilities similar to Illustrator, CorelDraw, or Xara X, using the W3C standard Scalable Vector Graphics (SVG) file format.
Made in Inkscape.
The download of icons (with the source, .svg file that can be opened in Inkscape):
Sagefans.net
Very cool! Open-Source rules!
Can you write some tuts?