Z-machine versions

There are at least 10 different versions of the Z machine out there:

• Versions 1-6 were created by Infocom in the 1980s.
• Graham Nelson made some minor changes in the 1990s to allow for larger story files, creating versions 7 and 8 of the spec. Most, if not all, modern Z machine interpreters support z7 and z8 story files.
• In the early 2000s, there was a great deal of discussion about new version 9 and 10 extensions, but these were never resolved.
• Adventures which are too big for even z8 can use Andrew Plotkin's Glulx virtual machine, which is generated using the same toolchain used to make most Z-machine adventures. Glulx has been around since the early oughts (first 2000s decade).
• In 2013, Zzo38 created (another) version 9 and 10 of the spec, with a number of extensions allowing even larger story files, finally giving Z-machines XOR support, and many other changes. These versions are not described in the 1997 Z-machine specification 1.0, nor in the 2006 Z-machine specification v1.1 (the most recent version), nor in the draft Z-machine specification v1.2; the only known Z machine interpreters that support these versions are Zzo38's own Aimfiz and Fweep.

Links

• This describes the non-Infocom extensions for versions 7 and 8 of the Z-machine
• This compares versions 1-8
• Spec for version 9 and 10 of Z-machine files (dead link)