RE: Time taken to impliment FOs?....

Subject: RE: Time taken to impliment FOs?....
From: "Didier PH Martin" <martind@xxxxxxxxxxxxx>
Date: Thu, 11 Feb 1999 09:59:13 -0500
HI Guy

I would draw to attention, the radical change MS made between IE3 and 4,
and the *huge* sweeping changes it made to its DOM, and to a leaser extent
it's rapid integration of XML and relatd technology in IE5.

Your are right Microsoft is very dedicated to XML they where among the early
adopters of this technology and showed concrete stuff in its early beginning
(ex: cdf co developed with Marimba)

With NS, what was looking like a slow moving progress quickly got turned
around when it turned open source, resulting in the quick emergence of

I am not so sure that Mozilla is moving as fast as you say. Each day I work
with the builds and cannot say that it is moving faster than before, even
worse, the progress is slower than when Netscape was moving full throttle. I
can say that the architecture, which is a work in progress, has a lot of
potential but we are doing catch-up with IE on the component facet. So,
truth is: IE is moving faster on new stuff than is Mozilla except on two
things CSS2 and RDF. But definitively, Microsoft is moving faster on XSL
(there is no working group doing XSL on Mozilla - no code yet - Do you

So the question is, would it take so very long for NS and MS to impliment

I cannot speak for Microsoft. But to implement FOs you need to separate your
display engine from the HTML interpreter. The browsers (if you look at the
code) still have a big dependency between the rendering engine and HTML
interpretation. On its side, Microsoft is working since a certain time on a
technology called Form+ that was called internally: Form3. That engine is a
generic display layout engine.

 The surest path is to first provide an API to the display engine like for
instance DOM2 even if it is unnecessarily verbose. An other API based on the
composite pattern would have been better (and the notion of property set
like, for instance the ADSI API has). It remains that the first step is to
create an object model for the display objects, CSS2 propose such a model
and is a lot more advanced with its concepts than XSL formatting object are.
In fact XSL FOs have to wait for CSS2 (in actual review) objects. When you
have this model in place and the corresponding API, you have independence of
the display engine toward any interpreter. So, a) the first goal for browser
engines is to de-couple the display engine from any interpreter b) have an
object model for each rendering object (independent of any language). Form+
can fulfill this for Microsoft and NGLayout for Mozilla. But on both side,
this is work in progress and it will take a certain time before having
something stable enough to be used. However, Form+ has the advantage that
the effort started 4 years ago and the team can leverage the knowledge they
gained from VB, VBA (FORM2 is included in VBA). NGLayout concepts are also
the reflect of good knowledge. So Mozilla needs volunteer to move faster on
this side. Volunteers? not a lot? it will take more time then :-)

It XSL became a Rec in August, this time next year might we be seeing the
betas of IE & NN 6 with FOs implimented?

For IE possible, For Mozilla we need more volunteers :-)

If the answer is that the browser manufacurer can move quickly to impliment
new technology into their browsers, then whether they do so or not becomes
less a matter of ability, and more a consideration of intent and will to
allocate development resource amidst competing product requirements. If
this is the case do we wish to weaken the insentive for their inclusion of
FO support into their browsers by weakening the position of FOs within the
XSL Rec?

No we don't. However W3C can release the spec in two pieces. The
transformation part ASAP and the FO part after - like a Version 1
(formatting) and a version 2(formatting objects). You know that it is a
usual practice to release things in milestones. I guess you do it yourself.
The biggest job for manufacturers is to implement a display engine which is
independent of any languages. After that, it doesn't take very long to
implement XSL FO. So, if you look at this from a PERT development chart
perspective, XSL Fo implementation is dependent on display engine with an
API for rendering objects implementation. The other PERT dependency is XSL
FOs with CSS FOs. After CSS2 workgroup got its feedback and the model
tested, XSL FOs could be based on this work. Here too we have a dependency
and not taking care of it conduct to a schizophrenic model and less chances
that manufacturers will implement it (W3C workgroups are fully aware of that
and I am reassured that they wont mess it but unify CSS and XSL FOs with the
same underlying model). Guy, there is a process there, we just want this
released a piece at a time and check for quality at each release.

About your projection for Mozilla, please go to and go in
the XML section. You'll get a feel of what's really going on there and what
is under current implementation. And, if you want, we need volunteers that
will indeed increase chances that Mozilla do have XSL with Fos in the
timeframe you mentioned ;-) Guha will be happy.

Didier PH Martin

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