i don't know if there's more than commercial software, but one i've seen is called CD Triangulations, by Barbara Henning, from Bear Paw Productions. i've checked a few places online and the lowest price i found was $23.99 on ebay.
JHittle.com offered it recently for $17.97. I can't find it in their online catalog, but I'll bet they still have it. I wouldn't be surprised if the price is still that low. it's Item no. bpp.56-2250_sgl
this is a link to their home page:
http://jhittlesewing.funoverload.com/sewing/catalog.php
you'll find their phone number and an email address you could use if you wanted to check to see if they still have it at that price.