BRLTTY gives a braille user access to the text consoles of a Linux/Unix system. It runs as a background process (daemon) which operates a refreshable braille display, and can be started very early in the system boot sequence. It enables a braille user, therefore, to easily independently handle aspects of system administration such as single user mode entry, file system recovery, and boot problem analysis. It even greatly eases such routine tasks as logging in.
BRLTTY reproduces a rectangular portion of the screen (referred to within this document as `the window') as braille text on the display. Controls on the display can be used to move the window around on the screen, to enable and disable various viewing options, and to perform special functions.
BrlAPI is a service provided by the brltty daemon.
Its purpose is to allow programmers to write applications that take advantage of a braille terminal in order to deliver a blind user suitable information for his/her specific needs.
While an application communicates with the braille terminal, everything brltty sends to the braille terminal in the application's console is ignored, whereas each piece of data coming from the braille terminal is sent to the application, rather than to brltty.