Joseph Kato.
I created Vale, the open-source prose linter that runs in the documentation pipelines of GitLab, Red Hat, Docker, NVIDIA, and more than 200 other teams.
I've built and maintained it since 2017. It has been downloaded more than 11 million times, and it's the subject of a book from The Pragmatic Bookshelf. I also wrote prose, a natural-language processing library for Go.
This site is where I write about language, public data, and data visualization, usually alongside a tool or dataset.
Where my work runs
6 of 208 teams · See them all ↗
- Video games
Epic Games
Checks the docs for Lore, Epic's open-source version control system.
-
GovernmentGOV.UK
Ships the UK government's technical style guide as a Vale package, which GOV.UK One Login enforces across its repos.
- Chips
AMD
Keeps a Vale style guide for the docs of ROCm, its GPU computing platform.
- Earth science
NASA
Checks its Earth-science data components against a NASA house style and plain-language rules.
-
Greek philologyPrinceton Logion Project
Checks the docs for its machine-learning tools for studying ancient Greek texts.
- Quantum computing
Qiskit
Checks IBM's Qiskit docs against the IBM Quantum house style.
Recognition
4 Cited · 4 Featured · 4 Press · 3 Adopted · 2 Award · 2 Grant · 1 Book · 1 Case study · 1 Video
- 2026
- AdoptedFly.io Sprites documentation
Fly.io lints its Sprites docs with Vale, on the Google style plus a house package
- AwardClaude for Open Source
Six months of Claude Max from Anthropic, for open-source maintainers
- Cited"A Second Set of Eyes": The Process and Challenges of Software Documentation Review
A GROUP 2027 interview study on how teams enforce documentation style in CI with Vale
- AdoptedRubin Science Platform
The Rubin Observatory lints its science platform docs with Vale
- CitedLLMoxie: Exploring Agentic AI for Scientific Software Development
A University of Washington agentic AI platform that uses Vale to check documentation prose
- FeaturedVale Linter: The Complete Guide for Docs Teams in 2026
A full guide to adopting Vale, from rules and styles through to CI
- FeaturedDocs Linting Guide
A documentation platform's linting guide, built around running Vale in CI
- CitedLinting Style and Substance in READMEs
A CHI 2026 paper that names Vale the closest prior art, and thanks me by name
- 2025
- BookWrite Better with Vale
Brian P. Hogan, The Pragmatic Bookshelf
- PressLinting-Stack für Node-Projekte
David König, heise online
- CitedComposition Pedagogy as AI-Native Coding: From Design Kit to Scholarly Framework
A writing pedagogy paper that proposes Vale for linting essays against APA, MLA, and Chicago
- AdoptedPublic writing guides built on Vale
Grafana Labs, Elastic, and the Jenkins Templating Engine publish their style rules as Vale
- GrantFLOSS/fund
$10,000, alongside FFmpeg, Zig, and Blender
- Case studyEngineering blogs on adopting Vale
Datadog, ING, Spectro Cloud, Contentsquare, Stream, Meilisearch, Stoplight, and Buildkite
- 2024
- PressProse Police
Koen Vervloesem, Linux Magazine issue 283
- PressVale: enforcing style guidelines for text
Koen Vervloesem, LWN.net
- FeaturedGolang Weekly
A newsletter about Go with ~80,000 subscribers
- 2023
- PressVale.sh – A Linter for Prose
Front page of Hacker News with 230 points and 82 comments
- GrantAppwrite OSS Fund
With Algolia, MongoDB, Fastly, and DigitalOcean
- AwardGoogle Open Source Peer Bonus
Nominated by Googlers for exceptional open-source contributions
- 2020
- VideoDocumentation as code: A Linting How To
A three-part Tag1 Consulting series, with a full episode demoing Vale
- 2019
- FeaturedTesting your documentation
A section in the Write the Docs community guide to documentation tooling
Languages
Share of code by language across 68 public repositories, weighted by bytes.
Education
Magna cum laude — 3.81 / 4.00
- Phi Kappa Phi
top 7.5% of juniors across all disciplines
- Pi Mu Epsilon
the National Mathematics Honor Society
Get in touch
If something here sparked a question, or you'd like to compare notes, write to me.
joseph@jdkato.io