What technology stack does Facebook use?

What technology stack do GDS of the world use?

• Clarification : GDS = Global Distribution System; like in the airline and hotel industry. What software stack do such systems use? I found a discussion on the WWW that some of these systems use mainframes et al. as the backend. However, I presume these systems were built a long time ago? Also, if one were to build a GDS for the hotel industry in these times, what stack would be most ideal?

• Answer:

  These systems were built on mainframes.   The story goes that airlines had been experimenting with systems that managed space availability on a batch basis.   Then one day the boss of American Airlines found himself sitting next to an IBM salesman and out of that meeting came Sabre.   That combined space availability, reservations and PNRs. The systems were originally built to handle just the host airline.   Then they started talking to one another which meant you could book beyond one airline onto another. Sometime in the 1970s the airlines in the USA began installing their terminals into agencies.   After some false starts and some government rulmaking in the USA the systems stopped biasing their displays to the owning airline, became neutral, added the ability to book cars and hotels and also started charging other airlines for bookings they made.   At this point everything was still mainframe based although the operating systems had moved from ACP to TPF.   Also they weren't using a single mainframe but a cluster and, in some parts of the cluster they were using MVS. These days the TPF cluster remains at the heart of the system but, increasingly, the systems around the mainframe cluster are beginning to use PC Blade clusters. There are already "Hotel GDSs" outside the GDS functionality within the airline GDS and, in some cases, the airline GDS connects to the hotel GDS which connects to the individual hotels.   I'm afraid I don't know about their technology.