[ubuntu-uk] 64 vs 32bit Applications

[Liam Proven]

On 1 June 2016 at 12:33, Nigel Verity <nigelverity at hotmail.com> wrote:
> I've recently gone over to 64bit Ubuntu versions on all my boxes and this
> raised a question. Does every binary object in the repositories have to be
> compiled twice - once for 32 and again for 64bit architectures - or can
> 32bit compilations run on a 64bit host?
>
> If they are separate versions is there a likelihood that some particularly
> obscure packages will fall by the wayside simply through being considered
> not worth compiling for 64bit? Perhaps there is a formal policy on this.

As a general rule, 64-bit x86 OSes can run 32-bit code. So it is
perfectly possible to run old binaries on a 64-bit OS.

E.g. Microsoft has not updated Skype for Linux in years, and it is
only available as a 32-bit binary, but it still works fine. However,
it requires a whole load of 32-bit libraries to be installed to
support it -- however, they come from the Ubuntu repositories and get
updated along with the rest of the OS.

-- 
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