Aran Paint Plus
This knitting design software includes an extensive library of stitches including cables, yarn overs, decorative increases/decreases, bobbles, slipped stitches for textured knitting. A demo version is available so you can try it out.
Chart Gen is an online knitting chart
Intwined Pattern Studio
For Windows or Mac, the built-in library includes over 200 patterns and stitches, or you can create your own.Although a demo is not available, there are videos that show how this software works.