The nature of online travel agency’s work implies interaction with multiple travel-related service suppliers, many of which have their own systems and different XML interfaces. Due to this, integration with each of the suppliers requires considerable amount of money and time.
GP software.travel undertakes complex XML API integration for you and offers a single standard interface for simultaneous interaction with multiple tourism product suppliers, some of them you can see below. You can also download the full list for convenience.
In order to connect any supplier in the list you need to have an agreement with them with access to their API (web-services).