[Solved]-where can I download this code-d3.js

as lars says, your best bet is to look at the source code. to do this, you can use something like chrome developer tools or firebug for firefox. i use the latter, so i'll take that as an example.

first, i'd right-click on the visualization itself, and click on inspect element with firebug. this will pull up the html, which is only semi-helpful, since it only shows the output rather than the javascript code which created it.

to get at the javascript, you can use firebug's script tab. most websites have more than one script, so you can hunt through the scripts being used by browsing through the dropdown menu in the second toolbar. the _buildchords.js script looks the most promising; that has some recognizable d3 code in it. you could check out the others to see what else they're calling (since it looks like there might be others - data.js, events.js, and so on).

happy learning.