Quote Originally Posted by handrawn View Post
reading PDF is AFAIK free, but editing/creating is not - the cost of the license to do this will be included in the purchase price of the xara program - commercially speaking this is worth the slightly higher asking price for most purchasers as PDF is one of the most common file types..
As far as I know, Xara, like most all others, purchase a library (most common is PDFLib) and use it. No money goes to Adobe for it.

Adding DXF support is the same. Most common is to license LeadTools, which I have used in the past.