Note: This was posted as an answer on Quora.
Android was originally founded by Andy Rubin in 2003 under the company name Android, Inc. It is correct that he previously worked for Apple and Microsoft, however he quit Apple, Inc. at about 15 years before the original iPhone was launched.
At 2005, Google finished their acquisition of Android, Inc. Hence, Google becomes the author of Android.
Two years after the acquisition of Android, Google launched the Open Handset Alliance (OHA), which lists companies, especially mobile device manufacturers, which ships some of their devices with Google’s Android OS (with Google Play Services). This leads to the fact that Android is not just owned by Google, but also all members of the Open Handset Alliance (including Samsung, Lenovo, Sony and other companies who makes Android devices).
As the core parts of Android are open sourced, anyone may obtain these parts freely as regulated by the license. As a result, many variants of Android are also made available, which lead to creation of custom ROMs and inspires Google to create the “Be Together, Not the Same” motto of Android.
Outside of Google and the Open Handset Alliance, there are also some companies and communities responsible for developing custom Android ROMs, which includes:
- Amazon: not an OHA member, while responsible in making the OS for Amazon Fire devices which are also based on Android.
- BlackBerry: joined as an OHA member, while they were responsible in porting the Android runtime for QNX and BlackBerry 10.
- Jide Technologies: responsible for Remix OS, which ports and modifies Android OS for usage in PCs.
- LineageOS: the community revival of the popular CyanogenMod custom ROMs.
- OpenMobile WorldWide: responsible in providing Android services and OpenMobile ACL Android runtime for Samsung’s Tizen (and probably BlackBerry’s QNX and BlackBerry 10 as well).
In conclusion, Android can actually be owned by anyone. You could grab the Android Open Source Project source code and do something with it. I feel that your question is incomplete though, as someone could own an Android OS the same way as owning a copy of Windows. Hopefully, this answer makes you understand about the diversity of Android OS, even though Google is currently the largest owner of Android.
