They were Apple 2 figures, which I think means US-centric for the early 80s. No, I wasn’t trying to imply anything about the UK – just trying to pin down what it meant to be a major software producer (even just nationally) in that time.
BTW, I keep forgetting to mention - one of the attempts at IF (or “Bookware”) at the time was Tellarium, and its parser was called BTZ. Better Than Zork.
Of course, it wasn’t, but this is how important Zork and Infocom were - important enough for a rival to be touting a (supposedly) better parser. Not even Better Than Infocom - Better Than Zork.
It’s gotta mean something.
Even if I am 2 year late (and 2 days a pay day short 
) I would have to correct you on that… “Telarium (corrected spelling, and aka Trillium)” DID NOT develop or use the BTZ parser… It was solely a Synapse engine… It was boughtt out by Broderbund which of course is now dead.