# Third-party test stories

`czech/czech.z5` is the unmodified compiled story from Czech 0.8.
`czech/czech.z3` was compiled from the same archive's `czech.inf` using Inform 6.44:

```
inform6 -v3 czech.inf czech.z3
```

- Czech archive: https://ifarchive.org/if-archive/infocom/interpreters/tools/czech_0_8.zip
- SHA-256: `d0795723e98563050575c4d3c08fdd29ade2543e132d8190255763e3bf6fef6a`
- Inform Windows archive: https://ifarchive.org/if-archive/infocom/compilers/inform6/executables/inform644_win32.zip
- SHA-256: `70900ea74795e8b7cccc39f7666cf9e26112dfda71845c99b569f79fd1f8ebc3`
- Retrieved 2026-10-31. Czech's full notice and license are preserved in `czech/README.txt`.

Czech permits use, modification and redistribution for any purpose with its notice preserved.
It is test data; no interpreter implementation was copied from Czech, Inform or another VM.

Praxix is downloaded only when `tools/conformance.py --praxix` is requested. The primary source is its co-author's repository, https://github.com/curiousdannii/if, pinned to Git blob `87f83a7ab4e33422807d0eff15d7b80c8e06771d`. IF Archive and its mirror are fallback sources. The story's SHA-256 is `bef3bdc2543cc7161833062855aa9bb1682db9eca69d9d36e9101347c21b48ac`, identical to `praxix.z5` inside the hash-pinned IF Archive distribution. Both cached and freshly downloaded content are verified before running.

Praxix is interactive; the runner feeds `all` and `quit` and checks its own assertion summary. Its Standard 1.1 visual colour test and Standard 1.2 capability test are skipped because this interpreter intentionally advertises revision 0.0. This is not a claim of complete Z-machine conformance.

The included `examples/lantern.inf` and `.z3` / `.z5` builds are original Apache-2.0 material. They use no Inform library. Zork and other proprietary games are not included.

Optional save-interchange tests were run against **Dumb Frotz 2.44** for Windows, compiled by Hugo Labrande and distributed by IF Archive. Archive: https://ifarchive.org/if-archive/infocom/interpreters/frotz/dfrotz.zip ; SHA-256 `4015db97afe0825c6fd115df1e758884d180f2e000166882ad17b287f21c6f04`. This GPL-2.0 reference interpreter is not distributed with this repository and is not a library dependency. `tools/interop.py` invokes a separately supplied executable and compares observable behavior and standard Quetzal files.