From the pdf linked in another post below: They use WKdm, a very fast compression. http://www.opensource.apple.com/source/xnu/xnu-1456.1.26/iokit/Kernel/WKdm.h

From the pdf linked in another post below: They use WKdm, a very fast compression. http://www.opensource.apple.com/source/xnu/xnu-1456.1.26/iokit/Kernel/WKdm.h http://www.opensource.apple.com/source/xnu/xnu-1456.1.26/iok... http://static.usenix.org/event/usenix01/cfp/wilson/wilson_html/node6.html http://static.usenix.org/event/usenix01/cfp/wilson/wilson_ht...