DISABLED FRIENDLY TECHNOLOGY
1]Technology is the usage and knowledge of tools, techniques, crafts, systems or methods of organization.
Technologies significantly affect AND ENHANCE human as well as other animal species' ability to control and adapt to their natural environments.
2].Disabled-friendly technology is essential for people with disabilities. Such technology has to be made available at an affordable price for effective participation of people with disabilities.
3]Unfortunately, most people, even the disabled themselves, in the third world countries are not aware that assistive technology may become their real friend in assisting them in everyday life.

FOR THE BLIND: 
1]Louis Braille  (January 4, 1809 – January 6, 1852) was the inventor of braille,[1] a worldwide system used by blind and visually impaired people for reading and writing. Braille is read by passing the fingers over characters made up of an arrangement of one to six embossed points. It has been adapted to almost every known language.
2]in 1821, Charles Barbier, a former Captain in the French Army, visited the school. Barbier shared his invention called "night writing" a code of 12 raised dots and a number of dashes that let soldiers share top-secret information on the battlefield without having to speak. The code was too difficult for Louis to understand and he later changed the number of raised dots to 6 to form what we today call Braille.
The same year, Louis Braille began inventing his raised-dot system with his father's stitching awl, the same implement with which he had blinded himself, finishing at age 15, in 1824.
Foundation – The Braille Cell
The six dots of the cell are numbered and are referred to as dot 1, dot 2, dot 3, dot 4, dot 5 and dot 6. This is helpful in describing the combinations of dots that make the different braille signs.
This simple six-dot arrangement is the invention of Louis Braille.each ALphabet or num is represented with the combi of 6 dots.
3] I would like to highlight in this article some assistive technologies for different types of disabilities; before that it is worth mentioning what an assistive technology means.
4]There is no specific definition of Assistive Technology (AT). It simply denotes any item, piece of equipment, or system that is used to increase, maintain or improve functional capabilities of individuals with disabilities.

5]They use software applications known as screen readers that turn the texts, events, and elements in applications and websites into synthesised speech. For example, when a user opens a new window in Microsoft Internet Explorer, a screen reader such as JAWS (Job Access with Speech) or Home Page Reader might say "new browser window".
6]Another AT for the visually challenged is refreshable Braille display, which may be used as an alternative to screen reader. These devices convert screen text into Braille and display the Braille on a number of cells comprised of independently controlled pins
 7]Braille embosser converts computer-generated text into embossed Braille output. Braille translation programs convert text scanned in or generated via standard word processing programs into Braille, which can be printed on the embosser. The results on thick paper are the individual dots that constitute Braille characters.

AT for the hearing challenged
1]Although hearing impaired individuals encounter less accessibility than the visually challenged do, they face tremendous difficulty in terms of learning, job access and social inclusion. These are due to the traditional way of learning.
2]However, computer technology has emerged as blessing to the hearing impaired. As computer prompts such as spoken messages and beeps can be misunderstood or go unnoticed by hearing impaired individuals, this problem is solved through the use of tools that produce visual warning when the system plays a sound and/or display captions in place of a spoken message. Light signaller alerts the computer with light signals. This is useful when a computer user cannot hear computer sounds. As an example, a light can flash alerting the user when a new e-mail message has arrived or a computer command has completed.
3]In addition, hearing impaired person can use TTY/TDD (Telecommunication Device for the Deaf), which is an electronic device for text communication via a telephone line, telecare, closed captioning, teletext and multimedia projector to address accessibility problem. Moreover, newer text-based communication methods such as short message service (SMS), internet relay chat (IRC) and instant messaging have also been accepted by the deaf as an alternative or adjunct to TDD.

PHYSICALLY HANDICAPPED:
1] JAIPUR FOOT Designed in, and named for Jaipur, India; the prosthetic leg was designed to be inexpensive, quick to fit and manufacture, and to be water-resistant.
2]The idea of making Jaipur foot was first conceived by Mr. Ram Chander Sharma (Masterjee) who designed and developed the foot and the limb.
The Jaipur Foot was developed in 1968. The  thesis submitted in 1971.

Sudha Chandran, Indian actress and dancer lost her limb, in an accident in 1982, and was fitted with the Jaipur foot and started dancing once again, her journey is the theme of the Telugu film Mayuri (1984), remade into a 1986 Hindi film, Naache Mayuri, both the films starred Sudha in the lead role.

SIGN LANGUAGE for the dumb:
Deaf and Dumb/Speechless people communicate by normal sign language, as they can still see. If you mean deaf and blind, they communicate by having someone tap out the sign language on their hand and then replying with normal sign language. The learning process is arduous[SIGN LANGUAGE]