But with open source, you always have an alternative. I can use the code unsupported, or I can find a clever open source hacker who can support it for me.

LXF: What about the argument that free software is crowding out commercially-made software, and stopping companies from making money?

GH: The government has always been concerned about... the Clinger-Cohen act, passed in the 90s, created a preference for commercial software in government, and what they meant by that was software that the government didn't make. What they wanted to do was to make sure that the government didn't end up doing itself something that could be done more effectively by the private sector.

So the rules say that before you go and build something, you have to look outside and make sure that nobody has already built one. So when government starts writing software, there's an immediate gut reaction that it's duplicative.

But, of course, there are cases where it makes sense for the government to be writing its own software, and Accumulo is a great example because Accumulo has features that didn't exist in any other project at the time.

The way they do charting, the way they do document storage, the way they do cell-level security, so I can determine for each individual piece of data who's allowed to talk to it or not. These features were unique to the Accumulo project, and the government did the right thing, because they open-sourced it.

And when you open-source it, it becomes a commercial item, because it's released under a commercial licence, which is the Apache licence. So it's under the Apache licence, which means that it's a commercial product. The senate is rightly concerned about crowding stuff out, but we have a case where it's not government-owned software anymore.

LXF: And rather than crowding out private enterprise, they've actually created a market for support services.

GH: There's a company called SQRRL, which closed its first round of funding a few months ago, wanting to be the Red Hat for Accumulo. So, here's an example of a government technology transfer that works. So I think that the senate concerns are valid, but in this case they're conflating government software with government-produced open source software, which are two very different things.

LXF: The other thing that we're always pushing as an advantage of open source is that it costs less, because you're not paying a licence fee. Is that an important factor, or is it irrelevant at government level? Because I imagine that the number of hackers you'd need to employ would be pretty expensive.

GH: Writing software is expensive, and it's even more expensive to maintain software. We've spent a lot of money writing code. Cost is often a factor in open source software for all the reasons you mentioned. It's often cheaper.

But I always caution people against saying that open source is always cheaper, or always more expensive, because although there are a number of advantages to the open source process it's always possible that a project is going to be very expensive to run.

Or bring it to your IT shop. So when we talk about saving money, it's important to look at what purpose you're using it for. So the economic value of open source is going to be very specific to which software project we're talking about.

All that said, there are a number of second-order effects to using open source that are definitely advantages.

And it's stuff like: you can always compete for maintenance; you can always fix it if it breaks; and the most important thing for me is that it gives you access to a whole bunch of innovation that would not be available to you otherwise.