It's useful to remember that Inform6 and especially its default library are limited in ways the Z-Machine itself is not. Inform7 is both better and worse with a

It's useful to remember that Inform6 and especially its default library are limited in ways the Z-Machine itself is not. Inform7 is both better and worse with a heavier default library, but the language is more expressive in some surprising places than Inform6's syntax most easily allows for. I'm not sure what MUDs you are specifically thinking about, but most things in MUDs that were single player are generally expressible in the Z-Machine with the right libraries. Writing those libraries might be a chore because maybe not enough people want much more than I6/I7 standard libraries. Also, it's an interesting experience to try to write in ZIL directly instead of Inform, now that there are a growing number of ZIL compilers and even some of the original Infocom games are source available in ZIL from leaks now. ZIL can be interesting to see a lower level idea of the Z-Machine. It's a weirdly capable virtual machine even in its most raw. That raw low level isn't what you'd expect if you expect something like Inform6 and the Inform6 standard library.