New cloud applications drive popularity of the AGPL license

Diaspora, the hottest new open source project, is licensed under the GNU Affero General Public License or AGPL. So are two other new, popular cloud applications, RapidFTR and ownCloud. Add to that popular forges Launchpad and Gitorious. According to Black Duck data, the number of AGPL projects grew 74% in 2010. The numbers and profiles of AGPL-licensed projects are becoming significant. So what is this AGPL thing and what does it mean to you?

First, a one-paragraph tutorial on open source licensing: All software is copyrighted. When you use software it is with the author's permission in the form of a license. Open source licenses allow users to not just use, but also to redistribute and modify source code. The philosophy behind them is to facilitate collaboration and contribution. Some open source licenses (known as copyleft or reciprocal licenses) require that any modifications to the software be licensed under the same license if they are distributed. One of those, GPL, is by far the most popular open source license; over 50% of the freely available software is under the GPL.

This modifications thing, which at first pass sounds innocuous, is, in fact, a big deal for technology companies that distribute software. Modification includes combining software with your own work. So, an ISV or embedded systems company may have a big fat proprietary software application with a tiny bit of GPL in it, and be compelled to license application under the GPL, thereby requiring them to make their all the source code available to anyone using software. For good reason, therefore, even product companies that are keen contribute to the community are wary of their developers using GPL code.

The AGPL requires a broader spectrum of companies to contribute, by addressing an opening that the distribution requirement has left for SaaS companies. An ISV that uses a SaaS model, thus avoiding the "d" word, can freely combine their proprietary code with GPL code and have no obligation to make their source code available. Google is a huge user of (and contributor to, we must note) open source software including GPL, but they get to keep the secret search sauce secret. If they were using AGPL code, however, this would not be the case. AGPL says you have to make source code for a program available to anyone "interacting with it remotely through a computer network."

Sounds like that was written with Google in mind, no? Well, maybe, but it was actually developed by a company, Affero, which had a network application and wanted to share while ensuring the propagation of its software. Affero means "contribute" in Latin. The company by that name had the mission of "bring(ing) a culture of patronage to the Internet." Their idea was modeled after the way a street musician or artist is compensated. Their software allowed authors to put their stuff out on the web and, essentially, stick out a hat. They wanted to share their software, but also wanted to ensure that users would contribute to it, and so worked with the Free Software Foundation to create the new license that bears their name.

For the most part, application development groups in Enterprises IT have been shielded from GPL concerns, because they, like SaaS companies, don't distribute software. This is not to say that Enterprises have not sought to manage their internal use of open source-there are plenty of other good reasons to do that-but licensing was further down on the list. Now the chances are increasing that a developer might incorporate AGPL code into an enterprise's proprietary application. With the rising popularity of the AGPL license, so will rise license compliance on the CIO's list of reasons to get their arms around their organization's use of open source.