Siddham
Siddham (Sanskrit, Accomplished or perfected) is the name of a North Indian script used for writing Sanskrit. Descended from the Brahmi script via the Gupta script. Siddham in turn gave rise to the Devanagari script.The writing of mantras, and copying of Sutras using the Siddham script is still practiced in Shingon Buddhism, in Japan but has died out in other places. It was Kūkai that introduced the Siddham script to Japan when he returned from studying Sanskrit, and vajrayana Buddhism in China, in 806. Siddham was influential in the development of the Kana writing system, which is also associated with Kūkai.
see also: Writing_system, Alphabet