You don't have to hunt down specialty "black" cocoa to make authentic Oreos; the only essentials are Dutch cocoa powder and a little baking soda to alkalinize the dough. Together, they make crispy wafers as inky and intense as the original, with a hint of bitterness to balance the sweet vanilla filling.

You open your browser to look at the Web. Do you know who is looking back at you? Over a recent week of Web surfing, I peered under the hood of Google Chrome and found it brought along a few thousand friends.