For DOS specifically, there is a market. So much of one that I can buy PCs with FreeDOS preinstalled. DOS, specifically, is used in many embedded applications t

For DOS specifically, there is a market. So much of one that I can buy PCs with FreeDOS preinstalled. DOS, specifically, is used in many embedded applications that do not require multitasking (digital display boards, point of sale systems, etc.). That's not exactly addressing the question, but one of the things that makes a successful business is finding a niche and exploiting it and though there may not be a mass market consumer market, there are definitely companies making money with "old tech".