What Is OpenHarmony? — Sorting Out How It Differs from HarmonyOS and HarmonyOS NEXT

Suppose someone asks you, “Huawei’s HarmonyOS is open source, right?” Could you answer accurately? The answer is “half right, half wrong”. What is open source is OpenHarmony; HarmonyOS is Huawei’s commercial product built on top of it. And HarmonyOS had its innards swapped out along the way, so depending on the generation, Android apps either run or they don’t.

Japanese-language material tends to blur these together, and misconceptions such as “Hongmeng = the Chinese version of Android” or “install OpenHarmony and HarmonyOS apps will run” have taken hold. From the position of someone deciding which OS to put into a device, that confusion does real damage. What you need to ask your suppliers, which licences your legal team cares about, which language your developers have to learn — all of it changes depending on which one you mean.

This article is aimed at engineers working on embedded equipment and business systems, and it sorts out the relationship between OpenHarmony, HarmonyOS and HarmonyOS NEXT on the basis of primary sources: the official OpenHarmony documentation and Huawei’s official announcements. The practical question of “is it a viable option to put into a device” is covered in the companion article, Is OpenHarmony a Viable OS for Industrial Equipment?.

1. The Bottom Line First

• OpenHarmony is an open source OS project incubated and operated by the OpenAtom Foundation. It is a foundation project, not a Huawei product, and anyone can obtain the source from the public repositories.¹²
• HarmonyOS is Huawei’s commercial OS product, and it is a different thing from OpenHarmony. It builds on OpenHarmony as its foundation, with Huawei’s own frameworks, app distribution platform and cloud services layered on top. The whole of the HarmonyOS source is not published.
• HarmonyOS changed its internals from generation to generation. The 1 to 4.x generations combined AOSP (Android Open Source Project) with OpenHarmony and ran Android apps, but from HarmonyOS NEXT (= HarmonyOS 5) onwards the AOSP-derived code was removed and Android apps no longer run.³
• The “NEXT” name stopped being used with HarmonyOS 6. At HDC 2026 in June 2026 the developer beta of HarmonyOS 7 was announced, and alongside it Huawei stated that “OpenHarmony has released more than 100 commercial versions”.⁴
• OpenHarmony is not a single OS product but a framework with “three system types”. From MCUs with as little as 128 KiB (mini system) up to application processors with 128 MiB or more (standard system), the configuration is switched within a single body of code.⁵
• The licensing is centred on Apache License 2.0 for the code. The LiteOS-A kernel is BSD 3-Clause and the documentation is CC BY 4.0, so it differs part by part. When adopting it, check the LICENSE of each relevant repository individually.⁶⁷⁸
• The community maintenance window is two years for a Release branch and 3.5 years for an LTS branch. And on top of that, the last LTS branch was 3.0-LTS in September 2021; every branch published from 3.1 onwards has been a Release. That does not match the premises of a ten-year device lifecycle.⁹¹⁰¹¹
• HarmonyOS smartphones and their app market are in practice China-centric. As of July 2026 Huawei’s global consumer site still shows a HarmonyOS 2 landing page, while HarmonyOS 6 is presented on the Chinese site. That said, HarmonyOS 5 and 6 firmware is distributed to wearables outside China as well, so “HarmonyOS 5 and later = China only” is not accurate.¹²¹³¹⁴
• There is a separate European lineage based on OpenHarmony. The Eclipse Foundation’s Oniro project is building extensions for European and global markets on top of OpenHarmony (Incubating as of July 2026).¹⁵

2. The Lineage on a Single Page

First, the overall picture. What gets called “Hongmeng (HarmonyOS)” covers at least three distinct entities.

And there is one more recent lineage that broadens your field of view if you know about it.

To put it another way, OpenHarmony is the “raw material”, and HarmonyOS and Oniro are “separate products made from that material”. Thinking of the relationship between the Linux kernel and Red Hat Enterprise Linux or Debian gets you close to the right granularity. Unlike Linux, though, OpenHarmony is a fairly vertically stacked package that includes not only the kernel but the UI framework and the app model as well.

3. What OpenHarmony Actually Is — What’s Inside

The official OpenHarmony documentation describes the project as “an open source project incubated and operated by the OpenAtom Foundation, whose goal is to build an open source distributed OS framework for intelligent devices in all scenarios”.¹

A four-layer architecture

The architecture consists of four layers, from the bottom: the kernel layer, the system service layer, the framework layer and the application layer.¹

• Kernel layer: a multi-kernel design in which you choose Linux or LiteOS according to the device’s resource constraints. A Kernel Abstraction Layer (KAL) hides the implementation differences and provides the upper layers with common process, memory, file system, network and peripheral management. Drivers are written against HDF (Hardware Driver Foundation), a purpose-built unified driver foundation.
• System service layer: distributed soft bus (DSoftBus), distributed data management, distributed scheduler, multimodal input, graphics, security, AI and so on.
• Framework layer: application frameworks for C/C++/JS, the Ability framework, and the ArkUI framework for JS.
• Application layer: system apps and third-party apps.

The important point here is that the “multi-kernel” design is what determines OpenHarmony’s character. Under the same OS name, LiteOS-M runs on an MCU while the Linux kernel runs on a rich device. When someone asks “what kernel does OpenHarmony use?”, you have to ask back: “which system type are we talking about?”

Three system types

The official documentation defines three basic system types.⁵

Starting from 128 KiB is what makes this OS unusual. The official documentation says it “supports RAM from hundreds of KiB up to the GiB class”.¹ The design is componentised, so you build up a configuration by leaving out the components you do not need.

Distributed capability as the core concept

The first characteristic the official material puts forward for OpenHarmony is device-to-device collaboration centred on DSoftBus (the distributed soft bus).¹ It is a common substrate that discovers, connects and networks nearby devices and transfers data regardless of the communication method, with distributed data management (synchronising data across devices) and the distributed scheduler (launching and migrating apps across devices) layered on top.

This idea of “treating multiple devices as a single super device” is also the foundation of HarmonyOS’s collaborative experience across smartphone, tablet and in-car systems. Put the other way round, if you are only embedding it in a single standalone device, you will not use half of OpenHarmony’s headline features. That matters when you come to the adoption decision.

Development boards and hardware

The community publishes support for 22 development boards.¹⁶ For the standard system there is the HiHope HH-SCDAYU200 with a Rockchip RK3568 and the MILOS_Standard0 with an NXP i.MX8M Mini; for the small system, the BearPi-HM Micro with an STM32MP157A; for the mini system, the Hi3861, STM32F407, ESP32 and the RISC-V HPM6750 — so the list includes chips from ST and NXP, not just Chinese SoCs. Some products carry descriptions that assume industrial use: the MILOS_Standard0, for example, lists “high-performance measurement instruments for industry and healthcare, industrial control and HMI, transport, disaster prevention and buildings” as its intended uses.¹⁶

4. What HarmonyOS Actually Is — The AOSP Hybrid Era and NEXT Onwards

HarmonyOS is Huawei’s commercial OS product. The thing to grasp here is that the same name “HarmonyOS” covers different internals from generation to generation.

• HarmonyOS 1.0 (2019): the first product it shipped on was not a smartphone but a smart screen (Honor Vision). This was the generation before OpenHarmony was donated to the OpenAtom Foundation, and it was not in circulation as a smartphone OS.¹⁷
• HarmonyOS 2 to 4.x (2021 to 2024): the generations rolled out on smartphones. They combined AOSP with OpenHarmony, and handsets of this generation could run both Android apps (APKs) and HarmonyOS apps. The reason the understanding “HarmonyOS is just the Chinese version of Android” spread in Japan is that this is how the generation genuinely looked.³
• HarmonyOS NEXT (= HarmonyOS 5, 2024): the AOSP compatibility layer and the Android libraries were removed, and Android apps stopped running. Only HarmonyOS native apps run.³ “Native app” here does not mean ArkTS alone. You can combine modules written in C/C++ against the Native API (NDK), and Cangjie (仓颉), a language Huawei developed in-house, is also offered as an option for HarmonyOS app development.¹⁸
• HarmonyOS 6 onwards (2025 onwards): the “NEXT” name was dropped and it became simply HarmonyOS 6. At HDC 2026 in Dongguan on 12 June 2026 the start of the HarmonyOS 7 developer beta was announced, along with the figures that HarmonyOS 6 had passed 66 million devices, registered developers had exceeded 11 million, apps and services available in the app store had exceeded 400,000, and HarmonyOS had become the second largest smartphone OS in China.⁴

In the same announcement, Huawei also said of the OpenHarmony side that “more than 100 commercial versions have been released”.⁴ In other words, OpenHarmony’s position for Huawei is that it is both the foundation of its own smartphones and a supply source from which other companies build industrial products.

Treat the regional question separately by device category

Regional availability is what bites in practice when you look at this from Japan, but lumping all devices together will lead you to the wrong conclusion. The distinction to draw is between the smartphone and app distribution ecosystem and the firmware of peripheral devices such as wearables.

• Smartphones and the app market are China-centric. The HarmonyOS 6 product page is provided on the Chinese site,¹³ while Huawei’s global consumer site (consumer.huawei.com/en/harmonyos/) is, as of July 2026, still the HarmonyOS 2 landing page.¹² It is fair to treat HarmonyOS native apps for NEXT-generation smartphones, and the market that distributes them, as effectively a domestic Chinese matter.
• On the other hand, the HarmonyOS brand does ship on devices outside China. Huawei distributes HarmonyOS 5 and 6 firmware updates to smartwatches in global markets too, so you cannot go as far as saying “HarmonyOS 5 and later = China only”.¹⁴

So if a Japanese company is talking about “building and distributing HarmonyOS apps”, that comes as a package with a business decision about the Chinese market. OpenHarmony, by contrast, is something anyone anywhere can obtain the source for and use, so the two should be treated as completely separate decisions.

5. Are “OpenHarmony Apps” and “HarmonyOS Apps” the Same?

In short: “the same lineage, but not the same thing”.

What they share is the skeleton of the app model: ArkTS (a language for declarative UI that extends TypeScript), ArkUI (the declarative UI framework) and Ability (the unit of app execution). Look at the release notes for OpenHarmony 6.0 Release and you will find items that closely resemble HarmonyOS feature additions: extensions to ArkUI’s layout capabilities, updating ArkWeb’s Chromium kernel from 114 to 132, the addition of AppServiceExtensionAbility, kiosk mode support and so on.¹⁹

Where they differ is everything around that. HarmonyOS apps are built on the assumption of Huawei’s HarmonyOS SDK and DevEco Studio, plus AppGallery as the distribution platform and the cloud APIs of HMS (Huawei Mobile Services). OpenHarmony has none of these. Therefore:

• You cannot install AppGallery apps on your own device running OpenHarmony.
• Nor is there any guarantee that an app built for HarmonyOS will run as-is on OpenHarmony hardware. You would have to check, one by one, whether each API it depends on is a Huawei extension or standard OpenHarmony.

If you adopt OpenHarmony for a device, the correct plan is that the apps running on it will be built by you (or by the vendor of the distribution you adopt). Deciding to adopt it in the expectation that “we can use the pool of Chinese apps” will miss.

6. How to Read Versions and API Levels

OpenHarmony versions are mapped to API levels, and there is a list in the README of the official documentation repository.²⁰

This list is the one carried in the documentation repository’s README, but the release notes index in the same repository lists newer entries still: 6.1 Release (8 March 2026) as well as 6.0.0.1 and 6.0.0.2.¹¹ Even within the official documentation the “latest version” statements sometimes fail to keep up, so when you pin down a version, look at the release notes index as well as the README.

The HarmonyOS side has API levels assigned in the same way, and Huawei publishes per-version release notes in its developer documentation.²¹ Because the numbering schemes are close, they are easy to confuse — but OpenHarmony API Level 20 and HarmonyOS API Level 20 do not necessarily refer to the same set of APIs. When you check a specification, always be conscious of which documentation you are reading.

7. Maintenance Windows — The First Number an Equipment Builder Should Check

The OpenHarmony community defines branch lifecycles as follows.⁹

• A Release branch has a two-year lifecycle (one year proactive maintenance plus one year passive maintenance)
• An LTS branch has a 3.5-year lifecycle (two years proactive plus 1.5 years passive)
• The proactive maintenance period is the period during which the community issues tagged versions on a plan and fixes defects and security vulnerabilities
• The passive maintenance period is the period during which no tagged versions are planned or released, and only security vulnerabilities and defects of critical severity or above are fixed

And the maintenance schedule for the branches actually published is as follows.¹⁰

There are three things to read out of this table.

1. The last LTS branch is 3.0-LTS (September 2021). There were LTS branches before that too: 1.1.0 LTS (April 2021) and its series (1.1.x LTS) remain in the release notes.¹¹ But every branch published from 3.1 onwards is a Release — that is, two years of maintenance.
2. Every branch in the table has reached end of maintenance as of July 2026. The 5.x line and 6.0 Release are not yet listed in this table.
3. This is an order of magnitude away from the premises of a device that runs for ten years. Compared with Windows 11 IoT Enterprise LTSC 2024 being supported for ten years to October 2034, you can see that the design philosophy is simply different.

This is not to say that OpenHarmony is inferior; it is that the model does not envisage “putting the community version straight into a product and leaving it there”. In real industrial adoption, the vendor of a commercial distribution maintains its own branch and sells that maintenance for money. When Huawei says “OpenHarmony has released more than 100 commercial versions”, it is pointing at the depth of that layer.⁴

8. Licensing and How to Obtain It

Licensing

OpenHarmony is not a single-licence project. It differs by repository.

When embedding it in a product, the principle is to check the LICENSE of each repository your own code actually links against, one at a time. Summarising it as “OpenHarmony is Apache 2.0, so we’re fine” will cause you to miss the GPL obligations in the kernel portion.

Obtaining the source

The source is fetched with the same repo tool used for Android. The procedure given in the official documentation is as follows.²

repo init -u https://gitcode.com/openharmony/manifest.git -b master --no-repo-verify
repo sync -c
repo forall -c 'git lfs pull'

Hosting is offered on gitcode.com, gitee.com and a GitHub mirror, with both SSH and HTTPS available.² If you want to pin to a release, switch the branch name to a version name such as OpenHarmony-6.0-Release, or to a tag (refs/tags/OpenHarmony-v6.0-Release). There is no special registration or authorisation procedure.

If you want to examine the structure before buying real hardware, there is a route through QEMU. The device_qemu repository carries emulation procedures for Arm Virt (LiteOS-A / Linux), Cortex-M4 (mps2-an386), Cortex-M55 (mps3-an547), RISC-V (riscv32_virt), Xtensa (esp32) and C-SKY (SmartL_E802).²²

9. The European Fork — Eclipse Oniro

Something Japanese engineers easily overlook is the Oniro project run by the Eclipse Foundation. The project page states explicitly that “Eclipse Oniro for OpenHarmony is built on top of the base layer of OpenHarmony, an open source project incubated and operated by the OpenAtom Foundation”, and sets out a direction of adding React Native support, an Eclipse Theia-based IDE, the Servo web engine and so on for European and global markets. The licences are Apache 2.0 and MIT, and the project state as of July 2026 is Incubating.¹⁵

For an organisation constrained by “an OS originating in China is difficult under our procurement policy”, it is worth knowing that an option in the same lineage exists under a European foundation’s governance, if only to widen the scope of the assessment. That said, its Incubating status, and the fact that its community is nowhere near the scale of OpenHarmony proper, are adoption risks in their own right.

10. Summary — Talk About the Three Separately

• OpenHarmony is the OpenAtom Foundation’s open source OS project. It covers everything from a 128 KiB MCU to rich devices with 128 MiB and up within a single body of code, and anyone can obtain the source. This is the thing you assess for adoption in a device.
• HarmonyOS is Huawei’s commercial OS product. The 1 to 4.x generations were AOSP hybrids and ran Android apps, but from NEXT (= 5) onwards AOSP is gone and it is a world of ArkTS apps only. In practice it is a product for the Chinese market.
• Eclipse Oniro is a European lineage built on top of OpenHarmony. It is still at the Incubating stage, but from the point of view of where governance sits it is a distinct option.

Once you can talk about these three without mixing them up, internal discussion gets a great deal more concrete — because instead of “shall we adopt HarmonyOS?”, you can translate the question into “which SoC do we put the OpenHarmony standard system on, with maintenance from which commercial distribution?”. The practical decisions beyond that — maintenance windows, hardware options, development environment and procurement, compared side by side with Windows IoT and embedded Linux — are split out into the companion article.

Related Articles

• Is OpenHarmony a Viable OS for Industrial Equipment? — Compared with Windows IoT and Embedded Linux
• Which Windows Should You Install on an Industrial PC? — A Practical Guide to Windows IoT Enterprise / LTSC
• The Practical Answer After Windows 10 End of Support

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Frequently Asked Questions

Common questions about the topic of this article.

Are OpenHarmony and HarmonyOS the same thing?

No, they are not. OpenHarmony is an open source OS project incubated and operated by the OpenAtom Foundation; anyone can obtain the source code, and it is distributed under open source licences such as Apache License 2.0. HarmonyOS, by contrast, is Huawei's commercial OS product, which builds on OpenHarmony as its foundation and adds Huawei's own frameworks, app distribution platform (AppGallery) and cloud services (HMS) on top. It is not the case that "because OpenHarmony is public you can read all of the HarmonyOS source", nor that "a device running OpenHarmony can install apps from AppGallery". The relationship between the Linux kernel and a commercial Linux distribution is a useful mental model.

What is HarmonyOS NEXT, and how does it relate to HarmonyOS 5 and 6?

HarmonyOS NEXT is the name given to the generation of HarmonyOS from which the Android (AOSP) derived code was removed; as a product version it corresponds to HarmonyOS 5. The HarmonyOS 2 to 4.x generations rolled out on smartphones combined AOSP with OpenHarmony, and Android apps (APKs) ran on them (the earlier HarmonyOS 1.0 was the generation that appeared in 2019 for smart screens). From NEXT onwards the AOSP compatibility layer is gone, and only HarmonyOS native apps run. "Native app" here is not limited to ArkTS: the C/C++ Native API (NDK) and Huawei's own language Cangjie (仓颉) are also options. In the following HarmonyOS 6 the NEXT name was dropped entirely, and it is simply called HarmonyOS 6. At HDC 2026 in June 2026, the developer beta of HarmonyOS 7 was announced.

Can I install HarmonyOS apps on a device I built with OpenHarmony?

Do not assume you can. OpenHarmony and HarmonyOS share a common lineage in ArkTS and ArkUI, and their API level numbers are assigned similar values, but HarmonyOS apps are built on the assumption of Huawei's HarmonyOS SDK and AppGallery, and a plain OpenHarmony environment has neither. Conversely, there is no guarantee that an app built for OpenHarmony will run as-is on HarmonyOS hardware. If you adopt OpenHarmony for a device, plan on the basis that the apps will be written by you (or by the vendor of the distribution you adopt) against OpenHarmony's APIs.

How long is OpenHarmony supported for?

The community lifecycle policy defines a Release branch as two years (one year of proactive maintenance plus one year of passive maintenance) and an LTS branch as 3.5 years (2 years plus 1.5 years). However, the last LTS branch was 3.0-LTS in September 2021 (there was a 1.1.0 LTS before that), and every branch published from 3.1 onwards has been a Release. If you use this OS in a product that is expected to run for ten years, as industrial equipment is, the community maintenance window is not enough on its own: you either buy vendor maintenance from a commercial distribution or you need an in-house capability to maintain your own branch.

How can a developer in Japan get started with OpenHarmony?

The source code can be obtained with the repo tool from mirrors on gitcode.com, gitee.com or GitHub, and there are no special procedures such as account registration or export permits. Official documentation is available in two languages, Chinese and English; there is no Japanese version. You can also run it under QEMU to examine the structure before buying a real board. The realistic starting point is the "Device Development" entry in the English documentation, beginning with deciding which system type (mini / small / standard) you are targeting.

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