Apparently, I don't think there is a lot of differences. All burning programs advance in versions to support new CD or DVD storage capacity.
I am using the Nero Express which can only burn CDs. It came with my CD-RW drive.
I haven't tried Nero 6, but I used to use the Nero 5 before, it's just a normal CD burner program supporting CDs only too. Anyone here tried Nero 6 can tell us what's in it? Does it support burning DVDs ? Single layer? Dual? Whatever?