DisplayML is an open

Open

- Philosophy :* Openness, term being used to define the basis of how various groups and organizations operate- Mathematics :* Open problem, a well-defined problem with no known solution in science and mathematics...

, free-to-use protocol

Communications protocol

A communications protocol is a system of digital message formats and rules for exchanging those messages in or between computing systems and in telecommunications...

 for encoding

Markup language

A markup language is a modern system for annotating a text in a way that is syntactically distinguishable from that text. The idea and terminology evolved from the "marking up" of manuscripts, i.e. the revision instructions by editors, traditionally written with a blue pencil on authors' manuscripts...

 display information for display device

Display device

A display device is an output device for presentation of information in visual or tactile form...

s. It is based upon XML

XML

Extensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....

 messages with a Request/Response model where the display device works as the server

Server (computing)

In the context of client-server architecture, a server is a computer program running to serve the requests of other programs, the "clients". Thus, the "server" performs some computational task on behalf of "clients"...

.

The interface

Interface (computer science)

In the field of computer science, an interface is a tool and concept that refers to a point of interaction between components, and is applicable at the level of both hardware and software...

 between systems and display devices has historically required encoded character strings

String (computer science)

In formal languages, which are used in mathematical logic and theoretical computer science, a string is a finite sequence of symbols that are chosen from a set or alphabet....

 which, though successful, can lead to complexity in creation and debugging. DisplayML is easy to understand, since XML is a human readable format. The protocol is applicable to numerous display devices using various technologies such as LED

LEd

LEd is a TeX/LaTeX editing software working under Microsoft Windows. It is a freeware product....

, LCD, Bi-stable Magnetic, VGA etc.

DisplayML does not handle security. The protocol can be implemented at different levels depending on the type of display.

The DisplayML protocol supports file transfer, which makes it possible to send fonts, pictures or software to displays.