“Headless automation for Internet Explorer”
Which looks like a port of (part of) the PhantomJS API to an environment that wraps IE by way of some .NET controls. (Also: V8 is in the mix somehow and/but/so not sure how that changes the equation w/r/t/ if the IE runtime is using that as the underlying JS interpreter or if it’s just some kind of bridge.) See also: SlimerJS : Gecko :: PhantomJS : WebKit
And speaking of SlimerJS: its API is also “PhantomJS-compatible” which raises the question of whether we need to be doing some work to create a “headless browser scripting” standard that we can reliably lean on, or if we’re just going to accept that PhantomJS came first and everyone is going to ape its API.