The document discusses the engineering of slidable user interfaces with a focus on the challenges and advantages of using multiple monitors and foldable screens. It highlights the limitations of current graphical user interfaces (GUIs) in effectively utilizing these multi-screen setups and presents a model-based approach called 'slime' for rendering GUIs across up to three screens. The conclusion notes various limitations of the slime approach and the need for further research into multi-user and multi-tasking scenarios.