Both are correct. John Resig first referred to it as a 'shiv' as a simple mistake (he meant 'shim'). But other folks kinda liked the implication of it being a crude, improvised weapon, so the 'shiv' name stuck. http://paulirish.com/2011/the-history-of-the-html5-shiv/

But we already have the shiv script at /media/js/libs/html5shiv.js included in the header of every bedrock page (those that inherit from the base template, anyway). So unless this one differs from the other one somehow (and if the two don't collide) this is probably a redundant dupe.