You can use a bare-metal machine with an Ubuntu Desktop or Ubuntu Server operating system to develop apps with the ctrlX AUTOMATION SDK.
The installation of the required packages, the ctrlX AUTOMATION SDK and some of the programming language installation scripts is equal to the procedure for a VirtualBox Virtual Machine.
You can find the informations in VirtualBox Virtual Machine from chapter 'Setup Standard Packages' to the end of the document.
Install the ctrlX AUTOMATION SDK¶
See here Install Sources from github