Infocom is a company created in June 1979 by Massachusetts Institute of Technology (M.I.T.) staff and students. This company has created well known adventure games (interactive fiction).
They choose an interesting solution to create their adventure games, they could have created games and adapt them on other platforms, instead they choosed to separate the game engine and the game data. So they only have to write an new game engine for each computer.
This game interpreter or virtual machine is called the Z-machine. It was created by Joel Berez and Marc Blank in 1979. The original compiler by Infocom has been lost but Graham Nelson has written in 1993 Inform which can ccompile the source of an adventure game for the Z-machine virtual machine or for the Glulx virtual machine (which removes some limitations of the original virtual machine by Infocom).
And now comes PunyInform v1.8 by Fredrik Ramsberg which is a library written in Inform 6 to create adventure game (pure text, no graphic support contrary to DAAD) using the Z-machine virtual machine which will run on 8bit computers (or more recent computers too). PunyInform has a parser, knowing of common verbs and a framework to write adventure games.
PunyInform is based on the Inform 6 library written by Graham Nelson. Its goal is to make easily adventure games in Inform 6, with a manual describing the differences between the official library and PunyInform..
Games using PunyInform can be compiled in z3, z5 and z8 format (z3 being the best format for 8bit computers, other formats have more features). Compared to the Inform 6 library, it means that there is no support for the Glulx virtual machine but z3 format is important as Inform 6 doesnt support it.
They are tutorials to write adventure game with PunyInform (end of the page).