Tom Trauth | 6 Nov 15:15 2011

RE: Is the xz format stable?


-----Original Message-----
From: owner-xz-devel@...
[mailto:owner-xz-devel@...] On
Behalf Of Lasse Collin
Sent: Sunday, November 06, 2011 9:11 AM
To: xz-devel@...
Subject: Re: [xz-devel] Is the xz format stable?

On 2011-11-06 Tom Trauth wrote:
> I am trying to submit a patch to an open source project to add xz
> support to it, but before accepting it the maintainer wants me to get
> a promise from the xz developers that the xz format is now stable and
> will have no backwardly incompatible modifications in the future.

It is stable in sense that new tools will always be able to decompress
old .xz files that have been created with a stable release of XZ Utils.
It is possible and even somewhat likely that new features will be added
in the future which old programs won't support.

Compare to the .zip format. It has got support for new compression
methods and other features over the years, including LZMA support.
When maximum portability is needed, people stick to the Deflate
algorithm which all non-ancient .zip implementations support.

> But he
> apparently had a bad experience with the lzma format changing its
> format several times and therefore does not trust xz.

(Continue reading)