For years a standard travel e-commerce approach to online booking involved licensing a "booking engine" for the Website. These booking engines began as a front-end to the GDS allowing the consumer to book air, car and hotel online. As travel e-commerce became more complex, booking engines often added business logic and customer profile information. An alternative trend to enable Website booking capabilities has an emphasis on the a robust middleware application. With this approach, the booking engine is nothing more than a presentation layer that sits on top of the middleware software and relies on it for all of its communication and business logic. The same middleware layer powers call center applications providing a common platform for online and offline customer interaction. A robust booking engine which contains customer profile information and business logic limits the use of the these functions for offline call center agents. Despite the hype around touchless travel, the offline customer agent still plays a critical role in travel e-commerce, especially for complex itineraries. Allowing this agent to pick up and complete partial reservations created by the consumer is an important role and turns call centers into customer care centers. This trend towards a robust middleware application continues to grow with many vendors providing this new functionality.