How can I search websites that uses specific javacripts? [on hold]

I'm trying to find websites that have installed a javascript, let's say jquery. I assume the indexing engine of Bing, Google, Yahoo, etc. store that kind of information. I would like to filter by that criteria. In my ideal search engine it would be something like this: climbing store +denmark script:"jquery" I found this question/answer in stackexchange but its no longer available. Thank you in advance