[array-filter](https://github.com/juliangruber/array-filter) is pretty popular, but it's tuned to be used in older browsers and it falls back on native `.filter()` when available, which is much slower. See [jsperf results](http://jsperf.com/array-filter-while-vs-for/2). The functions used in the benchmarks are the top performers, reduced down from 10 or 11 additional functions.