LAC is a lisp interpreter library. LAC is lightweight and extensible, and can be embedded in any program. The interpreter defines an API for adding new types and new procedures to the language runtime. This allows LAC to become the high-level control logic of a low-level library, but it also can also be used as a generic interpreted programming language. The language itself is heavily inspired by the small and simple LISP 1.5, with a few important differences: it is lexically scope and has a single namespace. Check sys.lac for the system library and the examples directory.