What is jQuery (edge) in jsfiddle.net?

In jsfiddle.net if one choose framework as jQuery or Mootools they will get an option for choosing jQuery ( edge ) and Mootools( edge ).

I googled it quite a bit but did not get any good answers. My questions are

1. Wha开发者_JS百科t are those versions?
2. How are they useful to the fiddle creator?

It is the jQuery nightly build from github...

jQuery JavaScript Library v1.6.3pre Live From Git (b22c9046529852c7ce567df13397849e11e2b9cc)

Here is the link: link (jsfiddle uses this)

Here is the jQuery github link: github-link

An edge build usually refers to some kind of "nightly" or not yet released build. The cutting edge, basically the latest source packaged up.