|Initial release||July 28, 2011|
Yun OS (simplified Chinese: 云OS; traditional Chinese: 雲OS; literally: "Cloud OS"), also called Aliyun OS (simplified Chinese: 阿里云; traditional Chinese: 阿里雲; pinyin: ālǐyún) is a Linux distribution designed for smartphones based on the Android Open Source Project. It is developed by AliCloud, a subsidiary of Chinese company Alibaba Group. Aliyun was released in China on July 28, 2011. The first device to run it was the K-Touch W700.
It took three years for AliCloud, involving 1,600 engineers, to develop Aliyun from the code-base of the Android Open Source Project. The company is challenging the dominant Android in China and is also looking to expand into Western markets.
As of May 2012, 1 million Aliyun-powered smartphones have been sold.
Aliyun revolves around the idea of bringing cloud functionality to mobile devices. According to the company, Aliyun will feature cloud-based e-mail, Web search, weather updates, and GPS navigation tools. In addition, the Aliyun services will synchronize and store call data, text messages, and photos in the cloud for access across other devices, including personal computers. Alibaba says it will offer customers 100 GB of storage at launch. The Aliyun would allow users to access applications from the Web, rather than download apps to their devices.
Relations with Android
According to Google, Aliyun is a forked but incompatible version of its open-source Android operating system. The company therefore attempted to prevent Acer Inc. from shipping an Aliyun-powered phone, arguing that Acer, a member of the Open Handset Alliance, had agreed not to produce phones running incompatible Android versions. Andy Rubin, who at the time was in charge of the Android division at Google, stated that while Aliyun is not part of the Android ecosystem, it uses runtimes, framework and various tools from Android. Though you can use the wallpapers of Yun OS in your Android phones. 
Aliyun OS incorporates its own virtual machine, which is different from Android's Dalvik virtual machine. Aliyun OS' runtime environment, which is the core of the OS, consists of both its own Java virtual machine, which is different from Android’s Dalvik virtual machine, and its own cloud app engine, which supports HTML5 web applications. Aliyun OS uses some of the Android application framework and tools (open source) merely as a patch to allow Aliyun OS users to enjoy third-party apps in addition to the cloud-based Aliyun apps in our ecosystem."
- Osawa, Juro (2012-09-09). "Chinese Software to Challenge Android - WSJ.com". Online.wsj.com. Retrieved 2012-11-17.
- "Alibaba Cloud Computing and Haier GroupLaunch Aliyun OS-Powered Smartphone : Global Growth Investors". General Atlantic. Retrieved 2012-11-17.
- Reisinger, Don (2011-07-28). "Alibaba OS-powered handset launching this month | The Digital Home". CNET News. Retrieved 2011-09-07.
- Andy Rubin. "We were surprised to read Alibaba Group's chief strategy…". Google+. Retrieved 2012-11-17.
- Brodkin, Jon. "Google blocked Acer’s rival phone to prevent Android "fragmentation"". Ars Technica. Retrieved 2012-11-17.
- Jon Brodkin (2012-09-17). "Pirated Android apps featured prominently on Aliyun app store". arstechnica.com. Retrieved 2014-03-17.
- Yun OS 3.0 Stock Wallpapers, News Exprezz.
- Moyer, Edward (2012-09-15). "Alibaba: Google just plain wrong about our OS". CNET News. Retrieved 2012-11-17.
- "Aliyun App Store Confirmed To Be Distributing Pirated Android Apps, Many From Another Pirate Site". Androidpolice.com. Retrieved 2014-03-18.