A great deal of mystery still surrounds Huawei's new Harmony OS software. It's still in beta, but when it emerges after April, it will be available as an "upgrade" for the Huawei Mate X2 foldable smartphone that launched today. 

However, the Mate X2 - presumably like other Huawei devices after it - will still launch using HMS (Huawei Mobile Services) and Huawei's EMUI 11 user interface which is built on top of a Google-free version of Android. Huawei can't use Google apps at present due to the ongoing US trade ban and it clearly hopes that Harmony OS will be a new start. 

Harmony OS has already appeared on other devices, but we've known for some time that it would appear on phones as well.

And indeed, it seems that after April 2021 Huawei will offer a route to Harmony OS for new and existing Huawei phones - presumably only fairly recent flagship ones though. It'll probably be a fairly easy process because - wait for it - Harmony OS is remarkably similar to Android itself. Earlier in the month ArsTechnica's Ron Amadeo got access to a developer build and to cut a long story short, it's essentially yet another Android fork. 

In a statement sent to Pocket-lint, Huawei says that "Huawei Mate X2 will run on HMS and EMUI 11 upon launch. HarmonyOS is currently in Beta testing, and our intention is to roll the software out to existing devices once the software has launched for consumers.

"Huawei Mate X2 will be in the first batch of Huawei smartphones that update to HarmonyOS in April."

The question is, will the update to Harmony OS be optional or a usual OS upgrade for existing flagship handsets?