How to get a list of preinstalled packages?
Every *buntu release has a .manifest or .list file that lists preinstalled packages. This file is located online.
For example:
- Lubuntu 20.04.1 64bit ➜
http://cdimage.ubuntu.com/lubuntu/releases/20.04/release/lubuntu-20.04.1-desktop-amd64.manifest - Ubuntu 14.04.5 32bit ➜
http://releases.ubuntu.com/trusty/ubuntu-14.04.5-desktop-i386.manifest - Ubuntu 12.04.5 32bit ➜
http://releases.ubuntu.com/precise/ubuntu-12.04.5-desktop-i386.manifest
...and so on.