I was wrong, after extensive research, it's Single user, as long as you using, you can install to as many as computers you have, you can install <--- meaning unlimited. It's honor system, there is no serial No. to install, technically you can make copy to sell to somebody, around $20-$40. My basic theory is at least Word Processing should including to every apple sold. My eMac had iWork installled from beginning, so make copy and share w/ friend. This Family pack ( 5 single person ) is rip-off, Single Person Pack is enough over paid to Apple.