mergician

Uniquely flexible and light-weight utility for cloning and deep (recursive) merging of JavaScript objects. Supports descriptor values, accessor functions, and custom prototypes. Provides advanced options for customizing the clone/merge process.

tree-kit

Tree utilities which provides a full-featured extend and object-cloning facility, and various tools to deal with nested object structures.

js-deep-clone

A JavaScript module for deep cloning objects and arrays, with support for dates, while handling circular references.