Yes, that's right: Highway 57 is no longer trading.
The site is not completely dead though...
There's still the odd page left here to explore,
or you can go to their own separate sites to find out about
Chris Sansom's musical activities
and various other personal projects, photos, etc.,
or Mary Sewell, London Blue Badge Guide.
And you can still play that amusing Flash logo animation
(as long as you promise to ignore the links at the end).