I see many old posts asking why there is no avast antivirus. I know u3 has avast. i also know that avast is not open source so did not originally fit the criteria for a portable apps. but i do believe that you have open things up for other free software to be used. So if avast is now doable i do wonder why it has not been done. if it has great can you point to it as i could not find cheers.