The Gurmukhī script is generally believed to have roots in the Proto-Sinaitic alphabet by way of the Brahmi script, which developed further into the Northwestern group (Sharada, or Śāradā, and its descendants, including Landa and Takri), the Central group (Nagari and its descendants, including Devanagari, Gujarati and Modi) and the Eastern group (evolved from Siddhaṃ, including Bangla, Tibetan, and some Nepali scripts), as well as several prominent writing systems of Southeast Asia and Sinhala in Sri Lanka, in addition to scripts used historically in Central Asia for extinct languages like Saka and Tocharian. Gurmukhi is derived from Sharada in the Northwestern group, of which it is the only major surviving member, with full modern currency.