[glhaynes]

Though they don't tend to get mentioned, I'd throw .app bundles into that list, too. The idea of moving an entire double-clickable app around as a single opaque icon (but that can be easily drilled into without special binary-parsing tools) has always appealed to me.

And couple it with fat/universal binaries, and you've really got something special. As someone who just installed their first instance of Windows x64, the difference between that world of having both "Internet Explorer" and "Internet Explorer (64-bit)" icons and a world where a complete system image from a 32-bit PowerPC can be booted seamlessly (with all apps still working) on a 64-bit Intel processor is stark indeed.