The Concorde, one of only two supersonic commercial airliners ever manufactured, took its last flight in November of 2003. Its Russian competitor, the Tupolev Tu-144, only flew with passengers for seven months, although it continued to be used for commercial flights and later for training and research.
Supersonic flight is expensive, noisy, and uses a lot of fuel. The folks at Boom are making one anyway. American Airlines, United Airlines, and Japan Airlines have signed on as partners.
In this video, which is surprisingly dull despite the dramatic soundtrack, Boom shows off the first subsonic flight of its XB-1 aircraft.
The XB-1 has been developed as a technology demonstration and testing aircraft for Boom's Overture, which they claim will have a cruising speed of Mach 1.7, carry 60-80 passengers and will be "optimized for zero carbon emissions." The details on that last bit are a little light, as sustainable aviation fuels reduce, but don't eliminate emissions.
Previously: NASA reveals secret supersonic airplane that quiets the sonic boom to a thump
