Since you mention HPGL, I would imagine that it supports RAW HPGL. Depending on how techie you want to get with it, could set it up as a virtual printer and in even programs like Ai, Draw, Inkscape can "print" directly from those programs. Now, that is more manual control, but it would preclude the need for a special driver. If it does support RAW HPGL.
If Signlab has a generic HPGL driver, could probably use that.
Again, the above methods may not allow for automation functions that people love to have in their cutting programs, but it is possible to work around those if it does support RAW HPGL and just parse what it needs. It is more techie, but doable. How, I was able to get cutters to work on Linux that don't have drivers for that OS (some do, most don't). Doesn't work for everyone, but that is just something that I was able to do to get it to work. Bottom line, is just how much effort you want to put into it.