# js-primer/js-primer

:book: JavaScript Primer - 迷わないための入門書

Repository: https://github.com/js-primer/js-primer
Canonical: https://ross.abutalabs.com/products/js-primer
Homepage: https://jsprimer.net
Language: JavaScript
License: CC-BY-4.0
License Family: other
Topics: javascript, ecmascript, book, tutorial, nodejs, browser
Last push: 2026-08-05T17:31:51+00:00

## Health v2 (maintenance only)
Score: 67/100 (v2, computed 2026-09-03T02:39:23.370411+00:00)
- activity 96, release rhythm 11, longevity 100
- inputs: {"age_days": 3865, "days_push": 28, "days_rel": 381, "gap_med": null, "n_releases_24m": 1}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2415, forks 230 (observed 2026-08-28T04:06:50.289938+00:00)

## What it is
JavaScript Primer is an open-source introductory book (CC-BY-4.0) teaching modern JavaScript based on ECMAScript 2015 and later, available as a free website and as a print/ebook edition. The repository contains the book's source, built with HonKit and continuously updated to track ECMAScript changes.

## Use cases
- learn javascript from scratch
- learn modern ecmascript 2015+ features
- refresh outdated javascript knowledge
- find a free javascript tutorial book
- understand nodejs and browser javascript basics
- prepare to read and write modern javascript applications

## When to choose
- you want a free, actively maintained introduction to modern JavaScript
- you know programming but find today's JavaScript confusing
- you prefer learning from a structured book with web, PDF, and print editions

## When to avoid
- you need an advanced or framework-specific JavaScript reference
- you want interactive coding exercises rather than prose
- you need documentation for a specific library or tool

## Facets
- artifact type: learning-resource
- maturity: active
- function: documentation
- domain: tutorials, web-development, programming-languages
- platform: browser
- tags: javascript, ecmascript, book, tutorial, open-textbook, honkit, japanese, nodejs, web-server

## Member repositories
- js-primer/js-primer (main) score 67

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:50.289938+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T02:33:11.774414+00:00, confidence not recorded.
  - readme: https://github.com/js-primer/js-primer (fetched 2026-08-28T04:06:50.289938+00:00, sha 9d09cadcd31f)
  - homepage: https://jsprimer.net (fetched 2026-08-29T10:14:07.730334+00:00, sha a4aa36b51776)
- Data as of 2026-08-30T08:39:29.467469+00:00.