i believe this tool (and the one in Lion/XCode) uses ipfw+dummynet, which is available also for linux/openwrt and windows at http://info.iet.unipi.it/~luigi/dum

i believe this tool (and the one in Lion/XCode) uses ipfw+dummynet, which is available also for linux/openwrt and windows at http://info.iet.unipi.it/~luigi/dummynet/ http://info.iet.unipi.it/~luigi/dummynet/ (you can find also some documentation material there).