[dagw]

'Sideloading' simply means not using the official Steam client to install a piece of software. Basically you switch to desktop mode and install it like you would install any random Linux application. No jailbreaking needed and you have full root access to the underlying Linux distro out of the box. That being said, navigating and installing software in desktop mode using just the controller is a major pain, and you really need to plug in a keyboard and mouse to make it easy to do. Also having a basic working knowledge of Linux and the command line is often required.