There are various distribution of GNU/Linux available now. I think every disto have a Live CD . So people can try it out and if they love it , can install it . So what I am talking is, it may not be possible to create a Live CD to try each and every distro and their newer versions . If you are a person like me , then you may love to use an alternative to boot from CD, something like a USB flash drive ( popularly called pen drive , thumb )  for its reusable .