This. And while we're at it, we shouldn't discount awk which had a profound impact on Self (and ultimately JavaScript) syntax, in turn. So much so, in fact, that the following pointless code (which doesn't even show JavaScript/awk regexp constants) is both JavaScript and awk:

    function f(x) {
      a[x] = "whatever"
      for (e in a)
        if (a[e] == x)
          return e
    }

Edit: but awk doesn't belong onto the list because it's far from dead