Is there a library which implements new Javascript/Ecmascript 5 methods for older versions?

Question

Although Ecmascript 5 introduces some completely new features, it also adds some new methods (bind, trim, map, etc.) which should be perfectly possible to implement (albeit slower) in current versions. Does a library exist which implements these backwards compatible features (and no more, excluding Prototype et. al.)

Answer 1

Kris Kowal and friends have built the es5-shim. It was part of Narwhal, but now lives on its own:

http://github.com/kriskowal/es5-shim/

Was: I've taken to using the global-es5.js shim from narwhal:

http://github.com/280north/narwhal/blob/master/engines/default/lib/global-es5.js

you'll have to take out the require("json"); line at the bottom, but other than that, it should be browser-clean.

Answer 2

Prototype and Underscore implement a lot of those.