On The CopyLeft Of DTDs

Makila writes: "I'm working on a project to digitize all the company marketing content, enabling us to re-use data for paper publishing, CD-rom, and Web publishing. The idea beyond that, as we are distributors, is to make suppliers contibute electronically their product descriptions, including technical specs and pictures, all elements that would be edited by us afterwards." To make a long story a bit shorter, Makila is looking for opinions on putting his company's DTD ^[?] under a free license. What pitfalls and advantages are involved in doing this?

"Writing a DTD is a challenge in itself (my company had never tried to go to the Web before, and never heard of XML until my project). To make the system work, we should then write software to adapt our supplier's data model to ours: for n suppliers we would need 2(n-1) correspondences (import and export) from their data model to ours which gets to be expensive on a large scale. Having a common model would help, especially for small companies not on the Web yet (those which rely only on paper data sheets for instance). My opinion, as there is no standard on our industry like RosettaNet, is that we could speed up things, and avoid babelization of XML tags by releasing our model with a Copylefted licence, lowering the cost and hassle for others on our market to build electronic publishing tools. Of course, there is a lot of money invested in our DTD, so what if competitors try to steal it?

Would the Copyleft of our DTD be a good idea?"

Comments

Standardization.

[istartedi]

A DTD is supposed to standardize data formatting, isn't it? Think less "copyleft" and more "standardized". This is one situation where the Artistic license makes sense, because it requires non standard versions to be labeled as such.

The Artistic license is so vague though, you might want to have your legal department draft something based on the BSD license, with a clause that hacked versions would have to be relicensed under a different name. That would give developers maximum freedom without compromising the standard. In other words, they could steal your code but they couldn't steal your brand name; similar to RedHat.

A GPL'd DTD would compel other developers to release refinements, but it would do nothing to protect your brand. Brand theft would be far more damaging than code theft.

GPLing DTD's makes no sense

[Hieronymus Howard]

I've both used and written a number of DTD's and releasing one under the GPL would really make no sense. The GPL freely allows anyone to modify your code, which is the last thing you want with a DTD. Since a DTD is a formal specification, you need to keep control over it. Ideally, once defined, it should never be allowed to change. If people can modify it as they like, then it becomes useless, since your XML documents may not conform to the modified versions.

If I were you, I would use something very similar to the Docbook copyright notice:

Copyright 1992-2000 HaL Computer Systems, Inc.,
O'Reilly & Associates, Inc., ArborText, Inc., Fujitsu Software
Corporation, Norman Walsh, and the Organization for the Advancement
of Structured Information Standards (OASIS).

$Id: docbookx.dtd,v 1.12 2000/08/27 15:15:26 nwalsh Exp $

Permission to use, copy, modify and distribute the DocBook XML DTD
and its accompanying documentation for any purpose and without fee
is hereby granted in perpetuity, provided that the above copyright
notice and this paragraph appear in all copies. The copyright
holders make no representation about the suitability of the DTD for
any purpose. It is provided "as is" without expressed or implied
warranty.

If you modify the DocBook DTD in any way, except for declaring and
referencing additional sets of general entities and declaring
additional notations, label your DTD as a variant of DocBook.

HH