Well, the package manager will show you your installed set of programs, or you can generate a list with the terminal and the utility that actually manages packages on a Debian based system (Debian-->Ubuntu-->Mint)
http://forums.debian.net/viewtopic.php?p=236027As to the idea of a list of the installed packages and I presume system services and library version and so on: what is a Linux distributor to do: create an attractive web site providing their iso files + forums, irc channels and then to also link to a portion that lists everything they include in their distribution set
A series amount of extra work
--especially if the are trying to provide timely releases of the Linux OS (kernel and a select set of applications
- This is why there is plenty of information on the internet about linux and the available open source applications..