Well, now that PDC is over I've had a chance to look into the issues and comments from our discussion the previous week. There continue to be a lot of comments about the licenses that we use for the Microsoft Office Open XML formats. The questions I've heard are:

  1. Are the licenses compatible with Open Source projects?
  2. Specifically are they compatible with the GPL?
  3. Is there a guarantee that Microsoft won't change the license out from under people? How accessible will these formats be 100 years from now?

As I've said in previous posts, I think the licenses are really a great step forward and for nearly all customers, there aren't really any negatives here. There are already a lot tools out there that evidently have had no problems working with our schemas. Sun for example chose the LGPL for Open Office. I’ve given you my thoughts on how I think our licensing program is compatible with the LGPL. In fact, I haven't seen a product yet that wanted to integrate with the Office schemas but wasn't able to. You can take a look at other formats, and they also have similar licenses.

Let's dig into the GPL issue as that's what folks were the most vocal about. I appreciate everyone's comments in the previous posts, and I wanted to specifically address Craig Ringer who has posted some very good comments on the GPL. People have asked for a yes/no answer for compatibility with the GPL, and the bottom line is I think he is right that the Microsoft license for the Office XML reference schemas is not compatible with the GPL. The GPL says that there can’t be a requirement that you give credit to the author of the program (something called “attribution”). The GPL also says that you can’t put a limitation on sublicensing IP rights. As Craig says, the Microsoft license has both these requirements, so it is not compatible with the GPL. Now, it is really up to you to decide whether or not those conditions are important to you, but from my point of view mentioning that the schema came from us and not sublicensing the IP rights seems to be totally reasonable. Those are really the only two issues I'm hearing that make them incompatible. There are other licenses similar to the GPL that don't have those added restrictions.

I know for a lot of people the GPL is sort of synonymous with “open source.” (I've read that the GPL is in the process of getting an overhaul by the way). I really don’t agree with that point of view. I think it is way too restrictive. There are tons of open source licenses listed on www.opensource.org. Are people saying none of those are any good except the GPL? Let’s also take this particular situation as an example. The Microsoft license says that you (developer) can write a program that can read and write the Office XML reference schemas, but you need to give Microsoft credit somewhere in your program simply stating that you've used our schemas. What’s wrong with that? I don’t see that as some super onerous restriction that should cause people to reject the license. I would say the same about the sublicensing issue. If the license is free and it’s available to anyone in the world, then what is the big deal? Once you write a program under the license, you are clearly covered.

Let me address a couple of other issues raised by Craig. He says:

... the license doesn't appear to be perpetually available. In other words, the terms can be changed at any time and apply to existing implementations. When software can be redistributed by end users and other companies, this is unlikely to work. Both the GPL and LGPL require that software can be redistributed by any end user.

The license actually is perpetual. Take a look, its right here: http://www.microsoft.com/mscorp/ip/format/xmlpatentlicense.asp. It says so right in the license grant and it is confirmed in the Q&A on the site. The Q&A is here: http://www.microsoft.com/Office/xml/faq.mspx

I don’t really understand the point about it being changed at any time. If you accept the license, then you have a deal. Microsoft can’t come back later and say the deal is different. I don’t see any restrictions in this license on distribution of programs created under this license.

Here is another comment from Craig:

- IP/patents. The license its self looks otherwise reasonable, but has a giant loophole by not disclosing what other MS IP/patents may be required and offering to license them under the same terms. An open license to the formats is useless if the terms of the patent license required to make use of it are unsuitable.

This is one where I’m sympathetic. The patent language is difficult to read, but when I walk through it, it seems to say that all patents and patent applications that are applicable to this space are licensed. This is better than a situation where a company discloses certain patents and says those are licensed but doesn't tell you about what else is there. Microsoft is saying all of its patents and applications are licensed in this space, so you have no need to worry.

While we’re on this topic, I think it’s important that you all take a look at the comparable situation with Open Document. A lot of folks just seem to assume that since it’s a standard, there are no IP issues and everything is very straightforward. Well, take a look at this: http://www.oasis-open.org/committees/office/ipr.php Sun seems to be saying that it may have IP in the Open Document spec. While Sun says it is willing to provide a royalty-free license, one would still need to ask Sun for a license. The license is not posted. It would be interesting to see, and I'll probably try to see if I can find it. The statement on the site alone reveals that at a minimum, they have at least one condition – you have to give Sun a reciprocal license.

It’s also being reported that IBM is really pushing this agenda: http://blogs.zdnet.com/BTL/?p=1887. What does IBM’s license look like? That would also be interesting to check out.

So, the answers to those questions listed above are:

  1. Yes we work with a large number of open source licenses (but not all).
  2. No, the GPL does not allow for the attribution and sub-licensing restrictions that the MS Office Open XML Formats licensing asks for.
  3. Yes the licenses are perpetual and you don't need to worry about them changing out from under you. The files you save will be freely accessible forever.

I hope that helps. Sorry we've had to spend so much time on this topic and not as much on the actual technologies and architectures of the formats. I'll try to get back into that ASAP since that's what most folks who've e-mailed me are more interested in.

-Brian