Whenever I use Firefox (latest compatible verison) on my trusty powerbook the fan has to go into overdrive! It happens even when reading just this site with no other programs open. I'm still using my wonderful seven year old Pbook G4 667! ) Terminal gives this if you have any idea what it means. PID COMMAND %CPU TIME #TH #PRTS #MREGS RPRVT RSHRD RSIZE VSIZE 3114 firefox-bi 90.3% 48:53.77 13 268 721 71.4M 49.1M 103M 257M Safari would only report a mid 20-30% CPU usage. I would stick with safari but it has a nasty habit of crashing unexpectedly.