Linux Repo
Debian 8 Jessie:
deb http://ftp.us.debian.org/debian/ jessie main contrib non-free deb-src http://ftp.us.debian.org/debian/ jessie main contrib non-free deb http://security.debian.org/ jessie/updates main contrib deb-src http://security.debian.org/ jessie/updates main contrib deb http://http.debian.net/debian jessie-backports main
Debian 7 Wheezy:
deb http://ftp.us.debian.org/debian/ wheezy main contrib non-free deb-src http://ftp.us.debian.org/debian/ wheezy main contrib non-free deb http://security.debian.org/ wheezy/updates main contrib non-free deb-src http://security.debian.org/ wheezy/updates main contrib non-free deb http://ftp.us.debian.org/debian/ wheezy-updates main contrib deb-src http://ftp.us.debian.org/debian/ wheezy-updates main contrib deb http://ftp.de.debian.org/debian wheezy-backports main deb http://mozilla.debian.net/ jessie-backports iceweasel-release
Kali 2.0 x86:
deb http://http.kali.org/kali sana main non-free contrib deb http://security.kali.org/kali-security sana/updates main contrib non-free
If there are any key issues, then run the following from commandline:
apt-get install debian-keyring debian-archive-keyring apt-key update
Fedora 22+
dnf install http://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm http://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-$(rpm -E %fedora).noarch.rpm
How To Query Repo's
Redhat Systems:
Search for package groups:
dnf group list <search term>