Cubic is a free and open source or custom Ubuntu based ISO file creator for Linux. Using Cubic, you can easily create your own Linux distro based on Ubuntu OS and it also supports Debian. It comes with build-in virtual command line environment, configure the the behavior of the Ubiquity installer, add or remove application to customize your Linux custom ISO, change the extension of the initrd file and more.
How to Install Cubic on Ubuntu Linux
You can install Cubic from the official Cubic Ubuntu PPA. Start the terminal app (ctrl+alt+t) and run below commands one by one. It will add Cubic PPA and install Cubic on your Ubuntu Linux system.
sudo apt-add-repository universe
sudo apt-add-repository ppa:cubic-wizard/release
sudo apt update
sudo apt install --no-install-recommends cubic
After the installation you can open it via the show applications menu or also run it via terminal app using below command.
Now download the source ISO from the Ubuntu website and start customizing and create your own ISO.
Note: It is not recommended to run Cubic inside a virtual machine. SO install and run Cubic directly on your host machine.