Formats for deck plan chits

Part of the goal of this project is to provide a variety of chits that others can use in generating their own deck plans.  The question is what formats should we support?  At a minimum I intend to provide PNG versions of all the images that can be used in almost any paint program.  I use XaraLX (when in Linux, my primary OS) for vector graphics and I suspect that it's native data format is not portable.  What vector graphics format do people use?