Towards EXSLT "1.0"

For a backgrounder on EXSLT, see my article "EXSLT by example". EXSLT was born of general contribution of the community on the XSL mailing list. Jim Fuller, Dave Pawson and Jeni Tennison started off a private thread to turn the list discussion into action, and I soon joined them. The result was the exslt web site, mailing list and initial set of extension specifications. We all agree that Jeni put the most work into it, and is the leading light of EXSLT, but she has been very busy lately (genius tends to occupy itself in overwhelming volume), and the rest of us have also had a hard time giving EXSLT the effort it desires. Last week, however, Jim Fuller and I decided to take some steps towards getting EXSLT back on course. In part, this is because some people want to get things moving on EXSLT for XSLT 2.0.

Here is a list of the things we're considering taking on in order to get to something we can call "EXSLT 1.0".

Clearing up licensing

I have proposed switching from the intended (but unstated) public domain to a CC attribution license for all EXSLT work products. It seems everyone accepts this, but the main remaining question is assignment of copyright. Some of the suggestions:

  • Assign to all the four managers. But do copyright decisions then have to be unanimous amongst us? Is it a problem that we reside in different countries?
  • Assign to Jeni Tennison alone. But does she have the bandwidth to dispatch all copyright matters?
  • Assign to the domain. I can't now find who suggested this to me, but my main question is the legality of such a move.

Creating some caretaker foundation for EXSLT is not really an option, because no one (I think) has time for all the work that entails.

Improving the information content of the EXSLT Web site

We need a good overview. We need news that we can keep up to date without too much effort, including references to the many good articles on EXSLT. We need better documentation for almost all modules (the perennial example is that users get confused as to whether or not they have to download stuff from in order to use the extensions). We need a better way to manage information about implementations. We need a FAQ. We should address outdated URLs from EXSLT specs (e.g.


We also need to think about the confusion between the namespaces URLs used in EXSLT. The extension URIs are different from the specification URLs. I understand how this distinction came about, but I think it has proven too confusing in practice. I suggest that we should put a RDDL gloss at all the namespace URL end locations, including a summary of the extension module and a pointer to the specifications.

Packaging EXSLT

We need to provide a package we can call "EXSLT 1.0". Something clear, recognizable and ready for download. It should include at least documentation on modules that proved useful over time. We should update the reference stylesheet implementations and examples (see e.g.


There have also been suggestions and proposals for new modules on the list, including:

My feeling is that we should go to 1.0 with the stuff that's already established on the site. We can add modules for a 1.1. release.

And then we would set up for EXSLT 2.0 extensions, which I understand people are itching to seed (I'll probably watch from the side lines as I work through my overall opinions on XSLT 2.0).

Jim has promised to jump-start all these tasks. I'll keep folks posted.

I welcome comments on this topic here on Copia, but if you really want to help, or want to engage in discussion with the overall community, please do join the mailing list and chip in.

[Uche Ogbuji]

via Copia
8 responses
IANAL, but I think that copyright ownership and CC attribution don't need to be strictly linked. In other words, it could be 'Copyright 2001-2005 by the original contributors' and at the same time all the contributors could agree to release it under a CC attribution license with the attribution to ''.

This is just as well, because at least in the US, actually assigning the copyright requires some fairly specific paperwork, which is more overhead that would be best to avoid, IMO.

One other thing that would help is making the site really, really low overhead to update--read something on the mailing list, and 30 seconds later have some small change online. One way to do this is a wiki format, even if it's editable only by managers and webmasters.
As I understand it, the formalized copyright rigamarole is rarely needed unless you forsee a good chance of infringement and want extra insurance for any potential case.  I don't think we need to worry about it in any case.

As for the Wiki, we can have a Wiki in addition to the main site, but I'm never likely to support the idea of a Wiki as the primary vehicle for  I've seen all the arguments, pro and con (for years now), and without wading thigh-high into the debate, my experience is just that it's too messy for what we want to do.
Hi Uche,

As a newbie with EXSLT, what appears to be one of the most important thing with the EXSLT project is that you communicate more on the benefit from it.

My first reaction when I saw it in 4Suite was to avoid using the extensions from EXSLT because I was afraid other XSLT vendors would not support it, and would make my code not portable.

I do think, you need to insist on the fact it is now quite well supported or not and to give more feedback on what is happening on the EXSLT world.

Anyhow, it's a great idea supported by expert in the area... it can't be bad :)

- Sylvain
The copyright owner of a document must be either a corporation or a natural person (so as such is out), but joint ownership between several natural persons is perfectly fine.

It's often believed that in cases of joint copyright ownership no owner can act without the others' consent, but this is exactly wrong-way-up: any author may act unilaterally as long as he is willing to be financially responsible to the other authors in distributing any profits.  This is a consequence of the general law of partnership, and obviously not an issue here.
Btw, Uche: thanks for the work on that effort. Between libxslt and EXSLT, I owe nearly all of the work I ever got done with XSLT to you guys and Daniel Veillard.

Yes, I've seen that it's hard for newbies to glean information on EXSLT from the site, which is why addressing the overview materisl is a priority.


I figured the assign-to-domain idea wasn't likely, but thanks for the clarification on joint copyright.  Based on that note, I think joint copyright of the EXSLT managers is the way to go.
Thanks Uche.

In France, you can assign to a domain name as long as the domain is also a name of a non profit organisation (1901's law).

- Sylvain
promised and delivered!

havent heard from you Uche? U must be experiencing vacation?