A good many languages have a written form in addition to the spoken form. The main benefit of having a written form is that the users of that language can express, share, and record their ideas and thoughts more widely. A written form of language makes it easier for the speakers of that the language to learn new things and skills outside of oral communication. It also helps them develop a pride in their culture and bring about an increase in self-esteem and self-reliance.
For a long time, sign languages had only a visual form, This is still true to a large extent, and, in the days before video technology became so readily available, there was little scope of recording anything anyone signed. People were creating stories and poems and songs in sign languages, but these could only be performed live and, consequently, got limited exposure. A few researchers then attempted to create written forms of sign languages, and two of the successful ones were William Stokoe and Valerie Sutton.
Valerie Sutton, a dance teacher with the Royal Danish Ballet, had invented Dance Writing in 1972. Her work interested a sign language researcher from Copenhagen University and, on his suggestion, she created SignWriting in 1974. It was not immediately embraced by the deaf community, but Sutton was persistent in her efforts to publicize and propagate her invention. She wrote about it, gave lectures on it, and published newsletters in it. SignWriting is now used in many countries, used in many sign language newsletters and publications, and for video and TV captions.