Yesterday, Google said that it had stopped Acer from launching a phone based on the Aliyun OS, which it described as a "non-compatible" build of Android. Since then, Google's Andy Rubin has continued to trade words with Alibaba, which worked on Aliyun with Acer. Responding to Alibaba VP John Spelich's assertion that Aliyun was "not a fork" of Android, Rubin said there was "no disputing" its status as an Android-based OS.

We agree that the Aliyun OS is not part of the Android ecosystem and you're under no requirement to be compatible.

However, the fact is, Aliyun uses the Android runtime, framework and tools. And your app store contains Android apps (including pirated Google apps). So there's really no disputing that Aliyun is based on the Android platform and takes advantage of all the hard work that's gone into that platform by the OHA.

So if you want to benefit from the Android ecosystem, then make the choice to be compatible. [It's] easy, free, and we'll even help you out. But if you don't want to be compatible, then don't expect help from OHA members that are all working to support and build a unified Android ecosystem.

While companies like Amazon are free to release forked versions of Android, Acer is part of the Open Handset Alliance (OHA), which means Google can step in to stop fragmentation. Alibaba has continued to claim that its OS is built on Linux, not Android, but it's unlikely we're going to be seeing it on a phone any time soon.