Right from the source: "Sets document-related variables once based on the current document" [1]. It's a very readable document and the comments give good overvi

Right from the source: "Sets document-related variables once based on the current document" [1]. It's a very readable document and the comments give good overview about quirks you have to be aware of. My personal opinion: not using jQuery (or similar library) for normal webpages is premature optimization and it will hurt more than help. [1] https://github.com/jquery/sizzle/blob/master/dist/sizzle.js#L489 https://github.com/jquery/sizzle/blob/master/dist/sizzle.js#...