Intended as a learning tool for developers looking to input bookings into TourCMS via API, very much NOT intnded for production use - unless you dislike your customers!
For an off the shelf, ready to go booking engine take a look at our hosted booking engine.
This is very much a work in progress, the code comments are currently being worked on and following that the UI could do with some updates. At a very basic level though it inputs bookings via API.
http://www.tourcms.com/support/api/mp/code/very_basic_booking_engine.php