Shared Source

I've been called lately by a few people on the fact that I normally talk about "open source" rather than "Free software". Since the leaders of both movements seem to agree that each category subsumes the others, I've felt free to assume notional equivalence between the two…

In that setting, I've chosen "open source" for a couple of reasons. First, I talk a lot these days about "open hardware", "open technology", and "open content". Even though the GPL dominates as a license in these settings, folks don't use the word "Free"; I'm guessing talking about "free hardware" and "free content" is just too confusing to tolerate.

Let me be clear. I use the GPL a lot. I encourage my colleagues to use it where appropriate. I always give my students a choice of any OSI-approved license for their work, including the GPL. While I'm not a license purist of any stripe, I think the GPL is a terrific contribution to the community and I fully support it. I just refer to it as "an open source license".


What got me thinking about all this afresh was meditation on the topic of "shared source". This is a term and license style, used by Microsoft, Sun, HP, and others, in which end users have access to source but quite restricted rights to use that access. Typical restrictions might be

Let us leave aside the merits of shared source licenses themselves for a moment, and consider just the name "shared source". I think it captures the fundamental distinction of the whole plan quite nicely.

Sharing is a very nice thing. That's something we learned in Kindergarten. When there is a limited resource that several parties desire, then out of benevolence, social conformity, or mutual benefit, the parties may agree to allocate that resource among them such that each party gets some predefined portion ("share"). The open source community shares all the time. We share hardware, money and effort.

The open source community doesn't share source, though, because source is not a limited resource. As I have written previously, metaphors often break down in the information world. What we do is give a copy of our source to anyone who wants it, to do (within reason) whatever they like with. Meanwhile, the ability of the giver to use the resource is entirely unimpeded. Sharing loses a lot of its meaning when instantaneously and at zero cost resource availability can be increased to meet the demand. Source is like that. Most world-of-bits things are like that.

What isn't like that—isn't infinitely duplicable—is the profit-making capability. So what the shared-source folks want to do is make a deal. You share your resources—your time, effort, and expertise in making the product source useful. In return, they will share their resource—a limited set of rights to use the source. There's nothing ethically wrong about that deal, and if both sides agree to share for the usual reasons—benevolence, social conformity, or mutual benefit—good for them. It's pretty clearly a different deal than the open source one, though. Open source is about distributing. Shared source is about sharing.

For my part, I don't have much to do with shared source. I like the open source deal better, and it just grows easier to find over time. I think this is because the open source policy reflects the reality of bits better than the sharing metaphor. I'm happy to share, but there's no need when there's plenty for everyone. (B)