Compression: pako

https://github.com/nodeca/pako

That's a high speed port of zlib C library to pure js. Why its awesome:

1. It allows you the same level of control (options, api), and guarantees binary equal result.
2. It's VERY fast. See benchmarks in readme, node's zlib bindings also exists there :) .

Packages like jszip, browserify switched to it from other implementations. js-git uses it too. When you need deflate/inflate/gzip operations in JS, there are no comparable alternatives.