Although Twitter’s technical “birth” was five years ago in March, Twitter opened its doors to the public exactly five years ago Friday. And to commemorate their baby coming into the world, the folks at Twitter are tweeting some pretty cool milestones. AllTwitter: As we noted in our piece, a lot has changed in those five years. And this new infographic from Visual.ly shows us just how much. NYT: The relationship between Twitter and the outside developers that build its apps is a little like the one between sharks and the small fish that latch onto their backs — beneficial for both, until it isn’t.