It is fully tri-modal in that it can be used visually, orally, or tactilely. Tactile access is through any refreshable braille display into which the GS code can be loaded. Voice access is through any voice screen reader into which the GS character table can be loaded. Math can be written and manipulated in the linear GS notation, which is a compact, syntactically equivalent subset of the well-tested family of TeX languages. A special table viewer allows two viewing methods.
Internal files provide information about objects in the figures.
Authoring tools are still being developed. Each process is given its own tty session, and the braille additions we have recently added to Screen allow the user to view these directly with a braille display without having to log in through a DOS machine. Currently, it works with the TSI Navigator 40, the TSI PowerBraille 40 and the TSI PowerBraille 80 braille displays. Screen runs under most UNIX variations, including the GNU Linux operating system available for PCs. Supported in part by the US National Science Foundation.