Nu is an interpreted object-oriented language. Its syntax comes from Lisp, but Nu is semantically closer to Ruby than Lisp. Nu is written in Objective-C and is designed to take full advantange of the Objective-C runtime and the many mature class libraries written in Objective-C. Nu code can fully interoperate with code written in Objective-C; messages can be sent to and from objects with no concern for whether those messages are implemented in Objective-C or Nu.