Blissymbolics were developed by Charles K. Bliss (1897-1985). Bliss originally called his invention "Semantography" and intended for it to be used as a universal written language which would enable speakers of different languages to communicate with one another.
Since 1971 Blissymbolics have been used mainly as a communication aid for people with communication, language and learning difficulties. Such people have limited or no ability to use ordinary spoken and/or written language but manage to learn Blissymbolics.
Blissymbolics Communication International - a charitable organisation which promotes and supports the use of Blissymbolics: http://www.blissymbolics.org