[1] Yes, multitude, there's at least: /etc/redhat-release, /etc/SuSE-release, /etc/debian_version, /etc/arch-release, /etc/gentoo-release, /etc/slackware-version, /etc/frugalware-release, /etc/altlinux-release, /etc/mandriva-release, /etc/meego-release, /etc/angstrom-version, /etc/mageia-release. And some distributions even have multiple, for example Fedora has already four different files.
PS : Also replace /etc/system-release and /etc/lsb-release
Use the more standard and universal
/etc/os-release. Read http://0pointer.de/blog/projects/os-release.htmlPS : Also replace
/etc/system-releaseand/etc/lsb-release