var win = typeof unsafeWindow != 'undefined' ? unsafeWindow : window;

// ==UserScript==
// @name           Make AutoPagerized Tweets Favoriteable
// @namespace      http://cxx.tumblr.com/
// @include        http://twitter.com/*
// @include        http://explore.twitter.com/*
// @version        0.3
// ==/UserScript==

var win = typeof unsafeWindow != 'undefined' ? unsafeWindow : window;
window.AutoPagerize.addFilter(win.jQuery.initializeTimeline);

Source for "Make AutoPagerized Tweets Favoriteable" – Userscripts.org

ここの

var win = typeof unsafeWindow != 'undefined' ? unsafeWindow : window;

と、以前utataneセンセーが教えてくれたフォーカスのやつ

// ==UserScript==
// @name tumblr text post stop focus
// @namespace http://d.hatena.ne.jp/Constellation/
// @include http://www.tumblr.com/new/text*
// ==/UserScript==
(function(win){
var original = win.onload;
win.onload = function(){
original.apply(win, arguments);
document.getElementById('post_one').blur();
}
})(this.unsafeWindow || this);

http://d.hatena.ne.jp/taizooo/20081029/1225238888#c1225293365

の

(function(win){
...
})(this.unsafeWindow || this);

って同じような意味なのかな? 引数の初期値? ここの "||"って OR とはちがうのか?