kmeleon is only for windows, you can run km on darwins through wine and through vmplayer(freeware) for mac os(x or 9)
check these links:
http://www.vmware.com/products/player/ (macs only:x/classic)
http://darwine.sourceforge.net/ (freebsd and osx)
http://wiki.winehq.org/MacOSX (osx only)
http://www.freshports.org/emulators/wine/ (freebsd only)