ReadWriteWeb

Once upon a time, whenever anyone asked, "But are there any big applications built on Rails?" The answer was usually, 43Things, anything from 37Signals, or Odeo. But over the past year, there's no doubt that if there is a poster child for Rails, it is now Twitter. With such notorious bouts of downtime, a worse poster child Rails could not possibly hope for. But is Twitter even the largest application out there running on Rails? Does it even matter?