Android isn't based on Linux. It's based on DangerOS

It kinda depends on how you mean &quot;based on&quot;; the general design on Android may be based on DangerOS (or, it sounds like, any of the Java-based embedded appliances that were so popular back then), rather than GNU&#x2F;Linux (because in this sense, it <i>couldn&#x27;t</i> be based on &quot;Linux&quot;), but in the sense of implementation Android&#x2F;Linux is absolutely based on a Linux kernel and even a quasi-unixy base userland before you get up to the not-really-a-JVM application layer.

The easiest way to settle this argument is to just run ARM Linux apps on Android via Termux + Proot: <a href="https:&#x2F;&#x2F;github.com&#x2F;adi1090x&#x2F;termux-desktop" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;adi1090x&#x2F;termux-desktop</a><p>While one can quibble over whether Android &quot;is&quot; Linux, it&#x27;s inaccurate to say that it &quot;isn’t based on Linux&quot; given how close their underlying systems are.

The integration with Linux goes even beyond system calls as others have noted. The entire app sandbox is based on Linux UIDs:<p>&quot;The Android platform takes advantage of the Linux user-based protection to identify and isolate app resources. This isolates apps from each other and protects apps and the system from malicious apps. To do this, Android assigns a unique user ID (UID) to each Android application and runs it in its own process.&quot;<p>So each app sandbox on Android maps to the traditional &quot;user&quot; accounts on Linux&#x2F;Unix systems.<p><a href="https:&#x2F;&#x2F;source.android.com&#x2F;security&#x2F;app-sandbox" rel="nofollow">https:&#x2F;&#x2F;source.android.com&#x2F;security&#x2F;app-sandbox</a>

While you can discuss what is proper definition of &quot;based&quot; it is definitely incorrect to say that Android <i>is not</i> based on Linux for it uses Linux kernel which is the most important part of the Operating System.<p>If we were so nitpicky we would have to say there is in fact no Linux, as most &quot;Linux&quot; distributions are GNU OS.<p>As nobody will question that Debian or Red Hat are Linux distributions there is no grounds to proclaim that Android isn&#x27;t one.

This is such a weird comment.<p>Android isn&#x27;t based on Linux, it just runs on top of it.<p>This feels like serious hair-splitting here. It definitely treads the fine line of &quot;What is an OS&quot;.<p>It&#x27;s worth mentioning that the author of the Quora answer is a retired member of the NetBSD foundation which may play into his perception of the situation.

&gt; DangerOS, which was a custom Java virtual machine living above a custom Danger written RTOS<p>RTOS means Real Time Operating System. The same Quora author explains what DangerOS was a bit better in another Quora answer [0]:<p>It was originally a very customized Java Virtual Machine (JVM) that ran on top of a scratch built RTOS kernel and provided support for Danger’s user interface and programming libraries.<p>Still unclear to me if this is true, and what the implications are. I see no mention of DangerOS elsewhere.<p>[0]: <a href="https:&#x2F;&#x2F;www.quora.com&#x2F;What-is-RTOS-and-why-have-no-one-mentioned-DangerOS-before" rel="nofollow">https:&#x2F;&#x2F;www.quora.com&#x2F;What-is-RTOS-and-why-have-no-one-menti...</a>

Android is really a mishmash of parts - a large chunk of the functionality in it&#x27;s &quot;Bionic&quot; libc is pulled from OpenBSD&#x27;s libc: <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Bionic_%28software%29#Components" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Bionic_%28software%29#Componen...</a>

That implies Android is not an OS, but an API and a set of services running on top of a Linux-based OS that&#x27;s embedded on each and every Android device ever sold.<p>That&#x27;s what Windows was, from 1 to 3.11.

I remember the SDK did not support all of the Java standard library, a lot of functionality were in danger.* packages.<p>When I first saw android, it seemed to me somewhat familiar. The vm that runs custom bytecode, etc.<p>Sadly, it looks like all the forums and mailing lists are now gone. I found a site with the source code of some apps, <a href="https:&#x2F;&#x2F;hipme.com" rel="nofollow">https:&#x2F;&#x2F;hipme.com</a>

I think it’s an interesting answer... to a different question: “What operating system Android conceptually descends from”.

On a side note, I used to work very closely with Marty at Samsung before his retirement. He is an inspiration for me and I really loved working with him at that time. At that time, lots of ex-Danger folks joined Samsung and later joined Google to work on Android OS.

This Quora answer seems really weird and the Wikipedia article doesn&#x27;t clarify much. I recall people talking about the hiptop using NetBSD pretty early on... I kindof get them calling DangerOS an OS though after reading through the answer, its kinda a meta-OS...

&quot;Please enable JavaScript and refresh the page to continue&quot; = No, fuck you.

And Maemo was not based on Linux, was based on Debian!!!111

BSD Unix :-(

Upvoted, not for the article itself but for the interesting discussion.