# eclipse-milo/milo

Eclipse Milo™ - an open source implementation of OPC UA (IEC 62541).

Repository: https://github.com/eclipse-milo/milo
Canonical: https://ross.abutalabs.com/products/milo
Homepage: http://www.eclipse.org/milo
Language: Java
License: EPL-2.0
License Family: copyleft
Topics: opc-ua, opcua, iec62541, java, client, iec-62541, industrial-automation, iot, milo, sdk, server, stack
Last push: 2026-08-19T12:19:12+00:00

## Health v2 (maintenance only)
Score: 97/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 98, release rhythm 94, longevity 100
- inputs: {"age_days": 3771, "days_push": 14, "days_rel": 42, "gap_med": 30, "n_releases_24m": 16}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1382, forks 473 (observed 2026-08-28T04:04:34.460239+00:00)

## What it is
Eclipse Milo is an open-source Java implementation of the OPC UA (IEC 62541) protocol, providing a high-performance communication stack plus client and server SDKs. It targets OPC UA 1.05 and is published to Maven Central.

## Use cases
- connect to an OPC UA server from a Java application
- build an OPC UA server in Java
- read and write industrial PLC data over OPC UA
- implement secure OPC UA client-server communication
- integrate factory floor equipment with a Java backend
- test against a public OPC UA demo server

## When to choose
- you need a mature, Eclipse-hosted OPC UA stack for the JVM
- you want both client and server SDKs in one project
- you need OPC UA 1.05 support with security features built in

## When to avoid
- you need OPC UA in a non-JVM language like C++, Python, or .NET
- you only need a lightweight protocol like MQTT instead of full OPC UA
- you require runtime compatibility with Java versions older than 17

## Facets
- artifact type: library
- maturity: active
- function: sdk, serialization, cryptography, networking, http-client, http-server
- domain: iot, developer-tools, apis
- platform: jvm, cross-platform
- tags: opc-ua, opcua, iec-62541, industrial-automation, client-sdk, server-sdk, java

## Member repositories
- eclipse-milo/milo (main) score 97

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:34.460239+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 2026-08-30T04:40:06.793526+00:00, confidence not recorded.
  - readme: https://github.com/eclipse-milo/milo (fetched 2026-08-28T04:04:34.460239+00:00, sha cd1b5bbb77b6)
- Data as of 2026-08-30T08:39:29.467469+00:00.