JavaScript app to search GitHub using JSON API
Looks good to me. You could cache the ul:

var repoList = $("&lt;ul&gt;").appendTo('#results');


So you don´t have to query the dom again when appending the list items.
Also it is better to build the list items in memory and only append the complete list to the dom. This way you only trigger one reflow.

So in the $.each loop I would 

repoList.append($("&lt;li&gt;somerepo&lt;/li&gt;"))


and then outside the loop

$("#results").html(repoList);