Aug 17

Andy Oram

Andy Oram

Skype and the GNU Affero GPL

It's providential that yesterday's Skype failure--which affects at least all of its free users, and which continues into its second day in most of the world--happens just as the Free Software Foundation is publishing its final draft of the GNU Affero GPL, and shortly after the release of the much-debated General Public License, Version 3. I think this massive failure in a service beloved and depended on by millions of people around the world will sharpen discussion of these two licenses.

I am one of the users who love and depend on Skype. I use the free service to talk to authors in Australia, Brazil, England, and the Ukraine. Yesterday we all found we could not log in. We run a variety of operating systems: Linux, Windows, and Mac OS X. So this outage was not caused by a Windows upgrade, as some have speculated, unless the central Skype login server was taken down by a Windows upgrade.

The company is inordinately secretive about the failure; one hopes they eventually open up a bit. All we know from their web site is that it blames the failure on "a deficiency in an algorithm within Skype networking software." Hence the relevance of the FSF's licenses.

I think the record of open source software shows that it gets fixed much more quickly than closed software. Among the millions of Skype users are thousands that would be happy to take a look at the login server's source code and suggest work-arounds or a redesign. I don't blame Skype for keeping the source code secret as part of their business plan, but perhaps they (and others) will start to look afresh at this advantage of free software.

The currently discussed GNU Affero GPL pertains directly to servers--although only servers that use free software licensed under this license. The Affero GPL differs from the regular GPL mostly in one simple clause that requires people deploying the software to offer any modified copy to "users interacting with it remotely through a computer network." This does not mean Google would have to provide all its algorithms to the public just because its servers run on Linux. (For one thing, Linux will not adopt the GLPv3.) But if Google altered a hypothetical GPLv3-licensed Linux filesystem or networking stack to support Google's work better, Google would have to release those fixes.

If the Skype problem lay not with the server but with client software, the value of open source software would be even more evident. Proprietary software creates a monoculture. The free software movement tends to create multiple tools to do the same thing, which can be confusing for people trying to choose the best audio player, PDF viewer, word processor, etc. But the diversity allows for a quick switch in case a crippling bug turns up in one project.

There's a lot of controversy over the network server clause, and doubts over its viability (I believe) led the FSF not to include it in the general GPL. But if the Affero GPL encourages some sites to let the public see the code they're running, it will benefit the software industry and the public.

tags: open source  | comments: 6   | Sphere It

Previous  |  Next

0 TrackBacks

TrackBack URL for this entry:

Comments: 6

  Frank Ch. Eigler [08.17.07 06:47 AM]

> But if Google altered a hypothetical GPLv3-licensed
> Linux filesystem or networking stack to support
> Google's work better, Google would have to release
> those fixes.

That's a real stretch. For one thing, GPLv3 !=
Affero GPLv3. For another, even if Google were
found to run some Affero GPL code in their services,
the license would not require the entire OS stack to
be published - only the Affero bits.

  Andy Oram [08.17.07 07:20 AM]

Thanks for tweaking my slapdash Google example. The whole thing was hypothetical, and I am not a lawyer so I didn't expect to provide a real example. The point is what Affero forces network services to do, which no other license forces them to do.

  Ukraine [08.17.07 09:25 AM]

Thanks for the update.

I am based in Ukraine and I had difficult in connecting to Skype yesterday. I had just updated by Skype version the day before and yesterday Skype would not connect. I was not sure if this was due to a problem with recent Windows upgrades or Skype itself.

The fact that Skypo is working today and I have not changed anything indicates to me that it was a Sip server issue and not my workstation.

I have come to rely extensively on Skype and if its service level deteriates I would have to consider adopting a new service provider. I wish Skype has Skype in for Ukraine...

  adam [08.17.07 10:00 PM]

Great to know there are other alternatives to Skype like www.jajah.coma nd

  Michael R. Bernstein [08.17.07 10:19 PM]

Frank, note that in the latest AGPL draft, it would also force the publication of any GPL code the AGPL code links to or was combined with.

  Peter Zaitsev [08.18.07 08:25 AM]

I think this is not about open source software but about centrally controlled systems vs open protocols.

As soon as you get different protocol implementations the design issues are more easily uncovered plus distributed processing makes it hard for all systems to fail.

Compare Skype for example to Email - open protocol and distributed media with no one party has control or responsibility of the whole systems.

Gmail did have downtime as well as most free mail providers but not the whole system for everyone.

Post A Comment:

 (please be patient, comments may take awhile to post)

Type the characters you see in the picture above.