Different types of official and unofficial sign languages are used by deaf communities around the world. Two of the well-known ones are American Sign Language and British Sign Language. These and many other sign languages can be written using SignWriting and Stokoe Notation. The invention of a sign language script and the discovery that sign languages have linguistics elements have gone a long way in the acceptance of sign languages as legitimate languages, not just as 'picture writing' as they were often considered.
American Sign Language (ASL) is very widely used by the hearing impaired as well as the hearing; apart from the deaf community, which comprises of deaf people as well as their families, friends, and interpreters, ASL is increasingly taught to hearing babies, toddlers, and children to aid in language and communication development. Other reasons for learning ASL include the desire to know a language used by thousands and to gain a foreign language credit.