While I don't know much about old what old stuff might be run by 'proper' tech people, I do know a DJ in Bristol who still mixes everything on an Atari ST. He's moderately popular, too, but that could be more due to his being 'part of the furniture' than anything else - he's been at it so long that the cover to one of his first releases was painted by Banksy before that would have cost a small fortune!