Chapter 1. Introduction to Web Services

The world is full of useful data and services offered by computer programs. But most of that data and most of those services are locked away. Web sites, designed for access by people and not programs, bury the information in an ever-changing morass of HTML. Communication protocols have been specific to applications and sometimes to operating systems. Precompiled libraries are useful only for particular programming languages on the system they were compiled for.

If you want to write a program to book a flight, check how much paid time off you have accrued, or find all the shows on TV that feature the stars of Buffy the Vampire Slayer, you're facing an uphill battle. All that data exists, but it's effectively inaccessible.