[DiapDealer]

I see fewer and fewer .xpgt files all the time. I'm sure ADE and RMSDK-based reading systems still honor them, but I get the distinct feeling they're falling out of fashion--a least based on the commercial EPUBs I purchase. Others may have differing opinions, of course, but I personally have very little use for them. They're handy for defining multiple-column layouts on larger screens, but on smaller screens, they're mostly used to annoyingly add more margin to already-quite-sufficient margins.