> Type Optimizations: One of the most important aspects of enabling performance on JavaScript is to create an efficient type system. The IE9 script engine uses

> Type Optimizations: One of the most important aspects of enabling performance on JavaScript is to create an efficient type system. The IE9 script engine uses many of the techniques common in modern dynamic language implementations, including type representation, polymorphic inline caching (also called type evolution or hidden classes), and efficient implementation of machine types. http://blogs.msdn.com/b/ie/archive/2010/03/18/the-new-javascript-engine-in-internet-explorer-9.aspx http://blogs.msdn.com/b/ie/archive/2010/03/18/the-new-javasc...