Cubic (Custom Ubuntu ISO Creator) is a GUI wizard to create a customized bootable Ubuntu Live CD (ISO) image. Cubic features an integrated command-line chroot environment, to make the customizations, and permits effortless navigation, backward and forward, through the ISO generation steps. You can create new customization projects or modify existing projects, and important parameters are automatically populated with intelligent defaults to simplify the customization process.
Pinguy Builder fork of Remastersys
https://www.ostechnix.com/create-custom-ubuntu-live-cd-image/