How do travel sites "get" airline fares?

[amrith]

How do travel booking sites (travelocity, expedia, itasoftware) get the database of airline fares?

Do they purchase a service from someone that provides them with a stream of fares and updates or do they go scrape screens?

I had assumed they purchased a feed from someplace but then I saw "The O'Hare Affair", a programming puzzle on ITA Software's web page and it seems like they scrape screens.

Ideas?

[nixy]

I believe most of them use Amadeus

http://www.amadeus.net http://en.wikipedia.org/wiki/Amadeus_CRS

[gaius → nixy]

Also http://en.wikipedia.org/wiki/Sabre_(computer_system)

[blinkit → gaius]

Also http://en.wikipedia.org/wiki/Worldspan

[joezydeco → blinkit]

Also http://en.wikipedia.org/wiki/Galileo_CRS (nee Apollo)

[Psyonic]

Trust me, ITA isn't scraping screens to get their data.