- Hugo. I usually use the most recent version of Hugo at the time of publishing, but it _should_ work with any version of Hugo v0.116.0 or later (v0.116.0 had an improvement to `where` that I might use).
- curl, for fetching some webring code and all my webmentions. **this requires authentication.** When running locally, it invokes `pash`, my password manager; when running in CI, it reads a file for a secret. You may have to modify `scripts/get-webmentions.sh` to avoid this.
- POSIX utilities: `grep`, `find`, `sed`, POSIX-compliant `/bin/sh`, etc. Tested to work with Busybox and GNU Coreutils.
- [Efficient Compression Tool](https://github.com/fhanau/Efficient-Compression-Tool) It's like zopfli but more efficient and faster. If you don't have it installed, it should be trivial to edit `scripts/compress.sh` to replace `ect` with `gzip` or `zopfli`.
Further tasks also use additional command-line utilities such as `sd`, `htmlq`, and a version of `xargs` that supports the `-P` flag (nearly all versions of `xargs` do, but it's not POSIX). I run all npm packages using `pnpm -s dlx` (similar to `npx`).
- A very recent build of the W3C's [Nu HTML checker](https://github.com/validator/validator) to validate the HTML and XHTML, available on your `$PATH` as `vnu`. I have a very simple shell-script wrapper for this that invokes `java -jar`.
- [jq](https://stedolan.github.io/jq/), to filter false-positives from the Nu HTML checker and to verify that JSON files parse.
- [HTMLProofer](https://github.com/gjtorikian/html-proofer), version 5 or later. Requires Ruby.
- Axe-Core, using the CLI and a headless browser (Firefox or Chromium).
- IBM Equal Access Checker, using the CLI and a headless Chromium. Runs on a patched version of the site with a modified stylesheet due to a bug (reported upstream).