Sapling grammar is a type of context-free grammar that is used for parsing and manipulating tree-like data structures. It is similar to Generalized Phrase Structure Grammar, but is more restricted in its form. Sapling grammars have a limited set of rewrite rules that can be applied to a tree in order to derive a new tree. These rewrite rules are called "productions" and are similar to the rules of a formal grammar.
Sapling grammars are used in computer science for a variety of tasks, such as parsing and compiling programming languages, developing compiler optimization techniques, and automatic tree manipulation.