I've tried Norton Antivirus 2007(not 360) in my costumer's pc & suprisingly it's really light but when I check the services they still got a lot services running like they used to. I wonder if it the 'lightness' can only fell in the desktop environment & not while running heavy applications. HERE'S THE BIG CATCH, I try download CCleaner using firefox & suddenly Norton DELETE the file while it's still downloading. Then I plug in my thumbdrive n somehow Norton give me weird message saying their autoprotect feature has REMOVE some file that has security risk. When I open my thumbdrive there's few file MISSING n those were OPEN SOURCE SOFTWARE.

My conclusion = Norton not open source friendly.