Please stabilize app-text/xchm-1.20. You can find a chm copy of Linux Device Drivers (released under CCSA 2.0) at http://dev.gentoo.org/~dirtyepic/pkgs/chm/oreilly_-_linux_device_drivers_-_3rd_ed_-_feb2005.chm for testing.
stable ppc
amd64 stable
x86 stable. Last arch, closing.