Lodash - Drop-in replacement for Underscore.js with upto 8x perf improvements

awesome. anyone who has had the time to dig into the source want to elaborate on this?:

" Lo-Dash's performance is gained by avoiding native methods, instead opting for simplified non-ES5 compliant methods optimized for common usage, and by leveraging function compilation to reduce the number of overall function calls. "

also, any chance of contributing the improvements back to underscore or is this different enough that that's not a possibility?