One of the most common complaints I hear from those migrating from that other operating system to OS X is the lack of decent alt-tab functionality.

That’s not to say that OS X doesn’t have an alt-tab — it does. And alt-tab-alikes abound. LiteSwitchX does a nice job of fixing OS X’s default inability to alt-tab back and forth between the two most recently foregrounded applications.

But in fact, it’s not the alt-tab, per se, that’s at issue. It’s the Mac concept of windows belonging to applications rather than existing semi-autonomously that causes unrest. While hopping from Mail.app to IE to BBEdit is a snap, it’s simply impossible to alternate between, say, Google and Slashdot residing in their own IE windows or Document1 and Document2 in Word. Some applications do provide their own local keyboard shortcut — Command-~ in both IE and Mail.app — but this is a rarity and varies from application to application. Other applications assign windows to Command-# keys, but who the heck can bear all that in mind while actually trying to get some work done.

My kingdom (or an honourable mention) for an alt-tab as nature intended it.

What alt-tab-alike do you use?