# apache/nuttx

Apache NuttX is a mature, real-time embedded operating system (RTOS)

Repository: https://github.com/apache/nuttx
Canonical: https://ross.abutalabs.com/products/nuttx
Homepage: https://nuttx.apache.org/
Language: C
License: Apache-2.0
License Family: permissive
Topics: nuttx, rtos, embedded, real-time, mcu, microcontroller
Last push: 2026-08-26T18:08:07+00:00

## Health v2 (maintenance only)
Score: 77/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 35, longevity 100
- inputs: {"age_days": 2454, "days_push": 7, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 4010, forks 1680 (observed 2026-08-28T04:08:32.244339+00:00)

## What it is
Apache NuttX is a mature, open-source real-time operating system (RTOS) for embedded systems with an emphasis on POSIX/ANSI standards compliance and a small footprint. It scales from 8-bit to 64-bit microcontrollers, supporting 15+ CPU architectures, 300+ boards, and 1500+ configuration templates.

## Use cases
- run a POSIX-compliant RTOS on a microcontroller
- build firmware for ARM or RISC-V embedded boards
- develop real-time IoT applications with a small footprint
- port Unix-style code to deeply embedded hardware
- evaluate open-source RTOS alternatives to VxWorks or FreeRTOS
- prototype embedded software using the NuttX simulator

## When to choose
- you need a standards-compliant, POSIX-like RTOS for microcontrollers
- your target hardware ranges from 8-bit to 64-bit MCUs
- you want an Apache-2.0 licensed, community-governed embedded OS
- you need broad board and architecture support with prebuilt configurations

## When to avoid
- you need a full general-purpose OS with rich desktop features
- your project requires hard guarantees on input validation and security hardening out of the box
- you prefer an RTOS with a large commercial vendor ecosystem and support contracts

## Facets
- artifact type: application
- maturity: stable
- function: embedded, concurrency, file-system, networking, security
- domain: embedded-systems, operating-systems, iot
- platform: embedded, iot, cpp, c
- tags: rtos, posix-compliant, microcontroller, real-time-operating-system, firmware, apache-software-foundation, real-time, arm

## Member repositories
- apache/nuttx (main) score 77

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:32.244339+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 2026-08-29T18:24:01.873638+00:00, confidence not recorded.
  - readme: https://github.com/apache/nuttx (fetched 2026-08-28T04:08:32.244339+00:00, sha f3d90f2c441b)
  - homepage: https://nuttx.apache.org/ (fetched 2026-08-29T09:17:06.267018+00:00, sha 4bbb83dab32c)
  - site_page: https://nuttx.apache.org/docs/latest (fetched 2026-08-29T09:17:06.276311+00:00, sha ba4886f85d95)
  - site_page: https://nuttx.apache.org/docs/latest/security.html (fetched 2026-08-29T09:17:06.278455+00:00, sha f283ed6ffe79)
  - site_page: https://nuttx.apache.org/download (fetched 2026-08-29T09:17:06.280637+00:00, sha 20701ad2c028)
  - site_page: https://nuttx.apache.org/articles (fetched 2026-08-29T09:17:06.282595+00:00, sha e15aedd076ae)
- Data as of 2026-08-30T08:39:29.467469+00:00.