Atli is a scripting language interpreter originally meant to be a quick way to develop a particular application's scripting language. Atli can also be used to write shell-like scripts to do tasks. Atli is a weakly typed language in which variables do not need to be declared before use. All variables are stored as strings and converted between string and number form automatically. Atli provides interfaces to cooperate with applications, so applications can exchange data and instructions with atli through a callback function.