SlackBuildsOrg/graphics/graphite2

Graphite is a system that can be used to create "smart fonts" capable
of displaying writing systems with various complex behaviors. A smart
font contains not only letter shapes but also additional instructions
indicating how to combine and position the letters in complex ways.

Graphite was primarily developed to provide the flexibility needed for
minority languages which often need to be written according to slightly
different rules than well-known languages that use the same script.