Acer's plans to use a third-party version of the Android operating system contravened its membership of the core Android industry group, according to Google.
The search giant moved to publicly defend threats allegedly made to Acer over the planned launch of its CloudMobile A800 smartphone, which would have run the Linux-based Aliyun operating system rather than Android.
Google said use of an incompatible version of Android contravened Acer's membership of the Open Handset Alliance (OHA), established in 2007 to promote open source Android against other platforms from Nokia, Samsung, Apple, Microsoft and RIM.
The alliance currently counts 85 different companies among its ranks and includes an agreement not to make phones that run incompatible versions of Android.
“Compatibility is at the heart of the Android ecosystem and ensures a consistent experience for developers, manufacturers and consumers," Google said in a statement.
“Non-compatible versions of Android, like Aliyun, weaken the ecosystem. All members of the Open Handset Alliance have committed to building one Android platform and to not ship non-compatible Android devices.
“This does not however, keep OHA members from participating in competing ecosystems,” Google says.
Acer summarily cancelled plans for the launch last week, a move the Aliyun developer, Chinese company Alibaba, slammed as regrettable.
Andy Rubin, Google’s senior vice president of mobile and digital content, stressed in a blog post that Android remains free for anyone to use as they would like.
However, he added that “by joining the Open Handset Alliance, each member contributes to and builds one Android platform — not a bunch of incompatible versions”.
Rubin took the argument further on Google+, saying “we were surprised to read Alibaba Group’s chief strategy officer Zeng Ming’s quote ‘We want to be the Android of China’ when in fact the Aliyun OS incorporates the Android runtime and is apparently derived from Android".
Though the Aliyun platform tries to be compatible with Android, Google’s analysis of applications from the Chinese company showed incompatibility between the operating systems.
Some of the apps in Aliyun’s application store appear to be knock-offs of legitimate Android ones, including “Angry Birds Space”, which looks like the original game from Finnish software house Rovio, but which is apparently developed by “leiguang888”.
Alibaba hits back
Alibaba hit back after Google's defence, accusing it of promoting a closed ecosystem, according to a statement from the Chinese company received by Ars Technica.
"It is ironic that a company that talks freely about openness is espousing a closed ecosystem," it said.
"Aliyun OS is not part of the Android ecosystem, so of course Aliyun OS is not, and does not have to be, compatible with Android. This is like saying that because they own the Googleplex in Mountain View, therefore anyone who builds in Mountain View is part of the Googleplex.
“Will someone please ask Google to define Android?"
An Alibaba spokesman told CNET that Aliyun was not a fork of Android, saying instead the operating system is built on open-source Linux.
“It can run some but not all Android apps," the spokesman said.