After the Duplicate Windows Server article this is its complementary for Linux.
Package managers and APT, YUM offer many ways to export selections of the software installed and the available documentation offer is so good that the best thing to do is just reference to the official documentation.
- Debian :https://wiki.debian.org/ListInstalledPackages
- Ubuntu : http://manpages.ubuntu.com/manpages/xenial/man8/apt.8.html or https://askubuntu.com/questions/17823/how-to-list-all-installed-packages
- RedHat: https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Deployment_Guide/sec-Listing_Packages.html