HarmonyOS

For IoT devices, the system is known to be based on LiteOS kernel; while for smartphones and tablets, it is based on a Linux kernel layer with AOSP libraries to support APK apps using ART through the Ark Compiler, in addition to native HarmonyOS apps.

The system includes a communication base DSoftBus for integrating physically separate devices into a virtual Super Device, allowing one device to control others and sharing data among devices with distributed communication capabilities. It supports several forms of apps, including the apps that can be installed from AppGallery on smartphones and tablets, installation-free Quick apps and lightweight Atomic Services accessible by users.

HarmonyOS was first used in Honor smart TVs in August 2019 and later used in Huawei smartphones, tablets and smartwatches in June 2021.

Reports surrounding an in-house operating system being developed by Huawei date back as far as 2012. These reports intensified during the Sino-American trade war, after the United States Department of Commerce added Huawei to its Entity List in May 2019 under an indictment that it knowingly exported goods, technology and services of U.S. origin to Iran in violation of sanctions. This prohibited U.S.-based companies from doing business with Huawei without first obtaining a license from the government. Huawei executive Richard Yu [zh] described an in-house platform as a "plan B" in case it is prevented from using Android on future smartphone products due to the sanctions.

Prior to its unveiling, it was originally speculated to be a mobile operating system that could replace Android on future Huawei devices. In June 2019, an Huawei executive told Reuters that the OS was under testing in China, and could be ready "in months", but by July 2019, some Huawei executives described the OS as being an embedded operating system designed for IoT hardware, discarding the previous statements for it to be a mobile operating system.

Some media outlets reported that this OS, referred to as "Hongmeng", could be released in China in either August or September 2019, with a worldwide release in the second quarter of 2020. On 24 May 2019, Huawei registered "Hongmeng" as a trademark in China. The name "Hongmeng" (Chinese: 鸿蒙; lit. 'Vast Mist') came from Chinese mythology that symbolizes primordial chaos or the world before creation. The same day, Huawei registered trademarks surrounding "Ark OS" and variants with the European Union Intellectual Property Office. In July 2019, it was reported that Huawei had also registered trademarks surrounding the word "Harmony" for desktop and mobile operating system software, indicating either a different name or a component of the OS.