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From "Dennis E. Hamilton" <>
Subject Discretionary ODF Provisions and Implementation Notes (was RE: Differences between OOO and LibreOffice.)
Date Sat, 02 Jul 2011 18:17:41 GMT
I think it is foolish to assign a metric to compatibility between OOO and LibreOffice, and
particularly between either and ODF.  If the 1% matters to me, it can be a show-stopper for
my interoperability needs.  The larger the take-up of *, the greater the number
of folks impacted by such things, including deviations attributable to platform, configuration,
and version of the software as well as the origin of documents that already exist.

The variety of contingent factors is rather extensive.

Adding to the degree of contingency is the extent of discretionary provisions in whatever
ODF specification a program's support is based upon.  There are places where provisions are
loose if not altogether underspecified, where provisions are explicitly implementation-dependent
in various ways, and where the conformance conditions are extremely flexible.

The sharing of a reasonably-common * code base promises alignment of discretionary
elements and even of extensions having nothing to do with requirements for ODF.  There is
a barrier of entry, so-to-speak, if the ways discretionary matters are handled are not made
explicit so other producers of ODF-supporting software can choose to align or at least to
deviate knowingly.  

I am not talking about the code being available for inspection, I am talking about explicit
statements that can be understood without having to examine an implementation.  That is what
provides for independently-derived interoperably-usable implementations based on an open standard.
 The work invested in arriving at such arrangements can also lead to valuable feedback to
the perfection of the evolving specifications for ODF.

One way to accomplish this is to provide implementation notes that explicitly account for
the conditions of support for ODF provisions and any deviations that also exist. I have only
seen this attempted by one producer.  Although that particular provision could be done much
better, I find it remarkable that this is the only case where it appears to be done at all.
The idea is to be accountable for discretionary matters in a way that adopters of software
can make informed choices about which products are suitable in a particular interoperability
situation, including support for already-existing documents for which continual conversion
is not an option.  This is also a way for a development team to be mindful of what their discretionary
choices are and how evolution of their code base needs to account for what those choices have

There is an opportunity for Apache to raise the bar in this respect.  And how
can one provide a reference implementation without such an account of all the discretionary
and contingent factors?  

I have heard it said that no desired quality of software is achievable in the absence of a
concrete measure for it.  Implementation notes are a way of assuring whatever the desired
quality of ODF support is to be, along with the discretionary provisions that are part of
that achievement.

 - Dennis

-----Original Message-----
From: Andrea Pescetti [] 
Sent: Saturday, July 02, 2011 07:38
Subject: Re: Differences between OOO and LibreOffice.

On 30/06/2011 Ian Lynch wrote:
> If I save an odf file from OOo it will open exactly the same in LibO.
> If that isn't true than I would be interested to know where things
> break.

Talking about 100% compatibility is probably exaggerated, since there
are portions of the ODF standard (e.g. table styles, if I recall
correctly) that are not implemented yet in either suite, and that could
be implemented with different accuracy/priority in future.

There are also cases of data loss originating from features that are
currently implemented in LibreOffice only, see

But of course these are corner cases and, if not 100% compatibility, and LibreOffice do indeed offer >99% compatibility.


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