From The Manufacturer/Wikipedia/People Smarter Than Us:
Pick up an XD® and you’ll be pleasantly surprised at how natural it feels. Whether you reach for a Full-Size, a Compact or a Sub-Compact, the first thing you’ll notice is how it nestles perfectly in your hand. Next, discover the ease with which you can acquire your target. Because it uses the same perfect grip angle as John Moses Browning’s proven 1911, the XD® points effortlessly and naturally.