NX is a highly flexible, Tcl-based, object-oriented scripting language. It is a descendant of XOTcl and was designed based on 10 years of experience with XOTcl in projects containing several hundred thousand lines of code. While XOTcl was the first language designed to provide language support for design patterns and to provide a highly dynamic programming environment, the Next Scripting Framework (NSF) and NX add to these features support for language-oriented programming.