When MATE is first installed as your computer's operating system, it is pre-configured so that both Orca, the screen reader, and Onboard, the on-screen keyboard, are already installed and running in the background. All you need to do to use them is press the keyboard shortcut detailed in each section below to turn the feature on. You use the same shortcut to turn each application off again.
If you want to use these features at the login screen, before MATE even starts, the accessibility icon in the upper right of the screen lets you toggle on and off Orca and Onboard. You can also use Orca 's keyboard shortcut Alt + Super + S to enable the screen reader to assist in the login process.