Orca is a free and open source, flexible, extensible screen reader from the GNOME project for individuals who are blind or visually impaired. Using various combinations of speech synthesis and braille, Orca helps provide access to applications and toolkits that support the AT-SPI (e.g., the GNOME desktop, Mozilla Firefox/Thunderbird, OpenOffice.org/LibreOffice and GTK+, Qt and Java Swing/SWT applications).