Source: layout/UnicodeLayoutEngine.js
/**
 * This class is used when GPOS does not define 'mark' or 'mkmk' features
 * for positioning marks relative to base glyphs. It uses the unicode
 * combining class property to position marks.
 *
 * Based on code from Harfbuzz, thanks!
 * https://github.com/behdad/harfbuzz/blob/master/src/hb-ot-shape-fallback.cc
 */

Source: opentype/shapers/ArabicShaper.js
/**
 * This is a shaper for Arabic, and other cursive scripts.
 * It uses data from ArabicShaping.txt in the Unicode database,
 * compiled to a UnicodeTrie by generate-data.coffee.
 *
 * The shaping state machine was ported from Harfbuzz.
 * https://github.com/behdad/harfbuzz/blob/master/src/hb-ot-shape-complex-arabic.cc
 */

Source: opentype/shapers/IndicShaper.js
/**
 * The IndicShaper supports indic scripts e.g. Devanagari, Kannada, etc.
 * Based on code from Harfbuzz: https://github.com/behdad/harfbuzz/blob/master/src/hb-ot-shape-complex-indic.cc
 */