The Internet has made publishing on a global scale almost effortless. That's the rhetoric, anyway. The truth is more complicated, because the Internet provides only a means of distribution; a would-be publisher still needs a publishing tool. A decade ago, people who wanted such a tool had three choices, all bad: a cheap but inflexible system, a versatile but expensive one, or one written from scratch. What was needed was something in the ­middle, requiring neither enormous expense nor months of development--not a single application, but a platform for creating custom publishing environments.