The technology has been developed by two software companies, one linked to Boeing and the other to Airbus. Seattle-based Tenzing, 30% owned by Airbus, is offering a lower cost, pre-packaged internet service where e-mails are sent and received in bulk around every 10 to 20 minutes rather than in real time. For a higher price, airlines can upgrade to a system providing live access. Virgin Atlantic, Singapore Airlines, Air Canada, Cathay Pacific and SAS have opted for Tenzing.