Tools

Compiles Markdown chapters into an online book with a table of contents, full-text search and themes, good for manuals, lecture notes and course material; agents can edit chapter files and rebuild to preview. Maintained by the Rust team; install a prebuilt binary or via cargo.

Automattic's offline English grammar checker: checks spelling, grammar and word choice locally in milliseconds without sending your text anywhere. Homebrew installs harper-cli for batch-checking files (still experimental) and harper-ls for editors. English only.

Fixes spacing and full-width/half-width punctuation in mixed CJK and English text, understanding 28+ file types including Markdown, YAML and strings and comments in source code. Lint mode outputs a diff or JSON for CI checks on localized copy.