Sharda is the original script of Kashmir. It evolved from the Western branch of Brahmi nearly 1200 years ago, when the language of Kashmir was developing into Kashmiri, with its peculiar intonations, variations and sounds. As a result, Sharda was imprinted with these vocal peculiarities, and became unfit for Sanskrit. Sharda, however, continued to be used for writing Sanskrit in Kashmir.

Sharda script was much in use in Kashmir, but also in North Western India (Gilgit etc.), the Punjab and Himachal Pradesh and even in Central Asia. Almost all the ancient Sanskrit literature of Kashmir is written in this script.

References:

- Ethnologue - Languages of the World
http://www.ethnologue.com/show_language.asp?code=bkc