Ink/Stitch - An Inkscape extension for designing machine embroidery patterns.
Crosti - make your own unique cross stitch design from custom image
Embird - Machine-Independent Embroidery Software
KXStitch - KXStitch is a cross stitch pattern editor by KDE.
Cstitch - free and open source program for creating cross stitch patterns from images
Mach3 - Mach3 is very popular among the Hobby CNC community.