It is an abugida developed from the Laṇḍā scripts, standardized and used by the second Sikh guru Guru Angad (1504–1552).
Gurmukhī ( Punjabi: ਗੁਰਮੁਖੀ, Punjabi pronunciation:, Shahmukhi: گُرمُکھِی) or Gurumukhī is an Indic script predominantly used in present-day Punjab, India. Without proper rendering support, you may see question marks or boxes, misplaced vowels or missing conjuncts instead of Indic text.