# espruino/Espruino

The Espruino JavaScript interpreter - Official Repo

Repository: https://github.com/espruino/Espruino
Canonical: https://ross.abutalabs.com/products/espruino
Homepage: http://www.espruino.com/
Language: C
License: NOASSERTION
License Family: other
Last push: 2026-08-21T09:54:41+00:00

## Health v2 (maintenance only)
Score: 76/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 98, release rhythm 35, longevity 100
- inputs: {"age_days": 4724, "days_push": 12, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2965, forks 767 (observed 2026-08-28T04:07:32.479308+00:00)

## What it is
Espruino is an open-source JavaScript interpreter and firmware for microcontrollers, designed to run on devices with as little as 128kB Flash and 8kB RAM. It powers a family of official boards (Puck.js, Bangle.js, Pixl.js, Pico) and lets developers program hardware interactively in JavaScript, often wirelessly via Web Bluetooth.

## Use cases
- program microcontrollers in javascript
- run javascript on embedded devices with tiny ram
- build bluetooth smartwatch or wearable firmware
- prototype iot hardware without c programming
- flash custom firmware onto esp8266 or stm32 boards
- control sensors and leds interactively from a repl

## When to choose
- you want to prototype or build embedded projects in JavaScript instead of C/C++
- your target hardware has very limited flash and RAM
- you want interactive REPL-based hardware development, including wireless via Web Bluetooth
- you're using official Espruino boards like Puck.js, Bangle.js, or Pixl.js

## When to avoid
- you need maximum performance or deterministic real-time behavior
- your project requires the full Node.js ecosystem or npm modules
- you're building a large application where a full OS like embedded Linux or a heavier runtime fits better
- you need guaranteed long-term commercial support for non-official boards

## Facets
- artifact type: library
- maturity: active
- function: interpreter, programming-language, embedded
- domain: embedded-systems, iot, programming-languages, hardware
- platform: embedded, iot, cross-platform
- tags: javascript-interpreter, microcontroller-firmware, firmware, embedded-javascript, wearables

## Member repositories
- espruino/Espruino (main) score 76

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:07:32.479308+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 2026-08-30T07:32:03.216104+00:00, confidence not recorded.
  - readme: https://github.com/espruino/Espruino (fetched 2026-08-28T04:07:32.479308+00:00, sha 579ed9dd42c6)
  - homepage: http://www.espruino.com/ (fetched 2026-08-29T09:47:14.403331+00:00, sha 4e6168ceeb3c)
  - site_page: http://www.espruino.com/FAQ (fetched 2026-08-29T09:47:14.412652+00:00, sha 40244d40222e)
- Data as of 2026-08-30T08:39:29.467469+00:00.