Re: Open source Ada OS?

[Ludovic Brenta <ludovic@ludovic-brenta.org>]

Anon wrote on comp.lang.ada:
> Dirk Heinrichs writes:
>>a...@att.net wrote:
>
>>> Most open OS that use CVS/SVN/GIT are based on BSD or LINUX or the AT&T
>>> old OS system.
>
>> RTEMS, Haiku, Marte, Lovelace, Hurd? Based on Linux? Based on BSD? I guess
>> not.
>
> First, there are 100s of openSource OS. A lot of them just store the source
> code in archived files such as zip or tar (gz or bz2) or etc.  

Wrong. They don't "just" store the source; they use a proper VCS for
development and publish snapshots as tarballs. Whether the VCS is
public or private is another matter. And this is true for almost all
software, whether proprietary or not. Software developers who don't
use any VCS are simply novices and you should not run their software
on your machine.

> Even closed source like Apple's OSX is directly based on BSD since Apple's
> Steve Job help create the openSource version of BSD and Apple admits that
> OSX is directly linked to BSD. Which also means that OSX is direcly based
> on AT&T old OS from 1969.

OK, so MacOS X is a derivative of UNIX.

> Linus Torvalds wrote Linux ( L plus an anagram of the true name of AT&T
> old OS that I nolonger use) to be a alternative to the high priced AT&T
> old OS with all of the features of AT&T old OS. And any OS that uses
> Posix, System V Api or other programs that was develope for an OS version
> that is based on BSD or AT&T old OS is directly or indirecly linked to
> BSD and AT&T old OS.

OK, so Linux is a derivative of UNIX, although it does not share any
source code with UNIX. It does share part of the design and the native
API, though.

> RTEMS    -- Includes supports for Posix and BSD sockets and
>             GNU based toolset GCC C and GNAT.

Just because an OS is POSIX-compliant does not make it a derivative of
UNIX.

Proof:
IBM's MVS is POSIX-compliant but is not a derivative of UNIX.
Microsoft Windows has a POSIX-compliant API but is not a derivative of
UNIX.
OpenVMS is POSIX-compliant but is not a derivative of UNIX.
GNU HURD is POSIX-compliant but is not a derivative of UNIX (it shares
neither the design nor the sources of UNIX).

> Torvalds may have create GIT. but when one downloads the Linux kernel
> one downloads the compress tar file.  That saves traffic because at
> the movement the current compress source kernel is around 50 MB and
> uncompress it could be 100 .. 200 MB worth of files to be downloaded.

No, I for one do not download the compressed tar file. I update my git
mirror. This saves a lot more bandwidth.

> Plus, except for Linux distro maintainers most people do not download
> each updated copy of the Linux kernel. Most may install two or three
> kernel within the life of the hardware to many changes to the kernel

Most people do not download the sources of the kernel at all. In fact
they do not download the kernel at all; they install the one from the
CD-ROM their geek friend gave them instead.

> for a simple patch it better just to download the complete current
> stable file.

By definition, the "complete current stable file" does not include the
"simple patch". The "simple patch" must be downloaded on top of the
"complete current stable file"; that's why it is called a "patch". If
you upgrade from one "stable" relase of the kernel to a later one just
because you need a "simple patch", you're doing it wrong. The new
"stable" release will contain many changes you are not interested in,
do not know about and may introduce new bugs.

--
Ludovic Brenta.