5. The computing device of claim 1 , wherein the compiler includes a code generator that receives a parse tree and generates the output program.
1. A computing device comprising: a memory; one or more processors operatively coupled to the memory; a compiler stored in the memory and executed by the one or more processors, the compiler operating to: receive an input script of a computer programming language, the computer programming language being associated with language metadata specifying runtime characteristics of the computer programming language; and generate an output program of machine code based on the input script and the language metadata; an interpreter stored in the memory and executed by the one or more processors, the interpreter operating to execute the output program based on the language metadata; and a language metadata provider to: produce one or more modifications to the language metadata based at least in part on language metadata commands to produce the one or more modifications to the language metadata, the one or more modifications including at least one of a new keyword, an operator, or a statement to be added to a grammar of the computer programming language, to provide the modified language metadata to the compiler and the interpreter, and to manipulate the language metadata at runtime and change language behavior.