Gurmukhi writing is especially prevelant for Sikh religious writings. It evolved from old Brahmi along parallel paths with Devanagari, but its present form was finalized by the second Guru of the Sikhs, Guru Angad in the early 1500s. 'Gurmukhi' translates literally as 'from the mouth of the Guru' in Punjabi. The earliest writing was for a series of religions hymns and poems. An alternate name for abugida is paimti, 'the thirty-five', for the number of consonant-vowel syllable combinations.

Punjabi itself is a tonal language, however Gurmukhi has no set mechanism for indicating the three tones of spoken word. Certain tones correspond to certain consonant series, however, and the voiced aspirates' alternate forms have evolved as an ad hoc method of indicating tonality.

Information sourced from Daniels, Peter T. Bright, William. The World's Writing Systems. Oxford: Oxford University Press, 1996.