+ CDN hosting for jQuery

https://cdnjs.com/#jquery happens to have older versions.

You could use CDNs more if you are willing to update to newer versions.  (Save hosting money, faster loading)  http://www.jsdelivr.com/ may host other scripts not on cdnjs.

BTW, [Lo-Dash](https://github.com/bestiejs/lodash) tends to be a bit faster than Underscore, & is more compatible with older browsers.