In contrast to OpenType shaping, Graphite shaping does not
specify a predefined set of shaping models or a set of supported
scripts.
Instead, each Graphite font contains a complete set of rules that
implement the required shaping model for the intended
script. These rules include finite-state machines to match
sequences of codepoints to the shaping operations to perform.
Graphite shaping can perform the same shaping operations used in
OpenType shaping, as well as other functions that have not been
defined for OpenType shaping.