Genscrnx is a wrapper for the fp 2.6 program genscrn.prg which creates programs from you 2.6 scx files. It was useful in fp 2.6 because you could add 3-d effects easily, put in conditional ifs to have controls show up (or not show up) on your screen, have tabbed pages and the list goes on.
To my knowledge, genscrnx has no usefulness in Visual Foxpro. If you search the file section for genscrnx you may come up with more info.
Kevin