[vox-tech] Apple & Linux

[Bill Broadley]

First, when someone names an operating system it most properly refers to the 
kernel.  You could for instance build a OS distribution with a linux kernel
and a BSD userspace (Applications, libraries, and filesystem).

In fact OSX just does this and uses a Mach kernel which has no relation to
any of the Free/Net/OpenBSD kernels.  It does use the BSD user space, so that
the binaries, filesystems, and libraries have a BSD flavor.

So, basically OSX is very unix like, but shares little with Linux.

But you might be surprised many things people associate with Linux are 
actually unix related.  X11, emacs, vim, firefox, gnumeric, openoffice,
ssh, java, azureus, etc. are not limited to linux.

In fact many applications are written to use other standards that control
their implementation of libraries, and most POSIX boxes have some BSD 
compatibility libraries, and most BSD systems have POSIX compatibility libraries.

So in general porting between any of the UNIXs isn't to bad, and there are
often groups that will maintain ports and provide relatively turn key 
libraries, binaries, and source distributions for your platform of choice. 
Especially OSX (there are a few), Solaris, HPUX, and of course linux.

With that said at least according to my skewed perspective the center of
said communities seems to be linux, and from the folks on other platforms
I often here complaints about linuxisms, dependency hell, and various
cases of assumed identity.  As long as you aren't doing something that
depends heavily on EXT3 (a filesystem), FUSE (a userspace API for 
filesystems), a linux kernel module, or linux binary things are likely
to be relatively portable.  Even in those cases there are sometimes
work arounds.

Alas the reverse is not true.  Source code for a graphical application 
developed for OSX or Windows usually doesn't work with linux.

As mentioned virtualization does allow access to other OSs applications,
but I wouldn't really call that compatibility.

Stuart Turner wrote:
> FreeBSD is not installed on Tiger, but Mac OS X runs on an a variant of BSD called Darwin. Darwin 
> is essentially open source (BSD is an academic license, not a reciprocal license like the GPL, and 
> allows Apple Inc to choose which components to remain open and which to keep proprietary).
> 
> ~ Stuart
>