Due to airline CRSs being based on mainframes, GDSs have been based on mainframes as well
Over the last few decades, GDSs have started providing direct connectivity from non-mainframe clients such as PCs
GDSs have also started leasing hosting space (hardware, software and connectivity) to airlines which do not want to create
and host their own CRSs
The advent of Internet has seen GDSs offer innovative products suited for accessing airline information over the Internet