[ale] difference between android and linux ?

[Michael B. Trausch]

On 08/12/2011 03:18 PM, Ron Frazier wrote:
> Forgive me if this is too simple or obvious to some.  What is the main 
> difference between Android and other Linux distros such as Ubuntu or 
> Fedora.  Can an Android device run other Linux's in general?  Can a 
> Linux device of another flavor generally run Android?

This is where "GNU/Linux" becomes useful in defining systems.

Most typical distributions that are built around the Linux kernel are
GNU/Linux systems, with extra stuff built around the GNU/Linux system.
For example, Slackware, Debian, RHEL, Ubuntu... they are all GNU/Linux
systems with differing strategies for package management and system
maintenance.

Android, OTOH, is _not_ GNU/Linux.  It uses the Linux kernel, but it has
a completely different runtime environment right on down to the C
library.  Most development for Android other than Android itself takes
places in the context of the Dalvik VM engine.

If you were to write an application that spoke "directly" to the kernel
and did not depend on kernel features that are disabled in typical
Android builds (and the application didn't have excessive hardware
requirements) then the application would run just as well on
Android/Linux as it would on GNU/Linux.  However, most applications
depend on certain things that exist in the GNU/Linux stack that do _not_
exist in the typical Android/Linux stacks, including glibc.

I could probably write a dozen pages more on this topic, but I'll hold
back unless there's interest in details.  You can also take a look
around yourself by checking out a copy of the AOSP (Android Open Source
Platform) and comparing it with the stack of virtually any GNU/Linux
distribution.

	--- Mike