By Ed Hammerbeck

With Linux’s growing popularity and IBM’s movement toward free software, the GNU General Public License (GPL) is becoming more of an issue for development managers. You may find developers lobbying to use this license, or other free and open source licenses, for a number of reasons, not the least of which is that it’s cool to be part of that community.

But before you join the GPL bandwagon—or any bandwagon that involves a license—you should be aware of several issues.

Free doesn’t necessarily mean free
GPL ensures that the software is free—meaning it remains available for public use and development. That does not necessarily mean you won’t have to pay something for the software. Although much of it is free of charge, software can also be sold under GPL. You just get the rights to distribute, copy, and modify it as you will once you’ve purchased it.

“The goal is to say you can have this software, but it is subject to certain licensing terms. And those licensing terms are that you have to let other people build on what you’ve done. So free software is not free as in cost; it’s free as in political,” explained David Loundy, the associate director of the Center for Information Technology and Privacy Law at the John Marshall Law School.

Live by free code, die by free code
One of the quirks of GPL is that if you incorporate GPL software or code into a product you create, your work then falls under the GPL.

This means that if you want to make something proprietary, you’ll have to either take out the GPL code or buy the license. While some companies, such as MySQL, will sell you a proprietary license, not all companies will. For instance, GNU products are licensed under the GPL by the Free Software Foundation, which created the GPL to prevent its work from being used in proprietary products. The Free Software Foundation was founded by Richard Stallman to develop and further the cause of free software, so it will not sell commercial licenses on any of its products, including GNU Linux.

In fact, the foundation is so serious about protecting the GPL, it uses an attorney to enforce misuse of the license on any code whose copyright is held by the foundation.

“We enforce the license all the time, but it’s a very interesting scenario when we do. When we find that somebody’s violating the GPL, it usually means they’re failing to distribute the source code for the program to the user. Or they’re failing to allow the user…to copy and distribute it,” said Bradley Kuhn, vice president of the Free Software Foundation.

The foundation will notify the company that it’s out of compliance with the license. Often, the companies ask to buy out the license.

“We tell them, well, we don’t want money. What we want is the community to be respected. We want you to turn it into free software, and that’s how you comply with this license,” explained Kuhn. “The other option is to remove all of the GPL’ed portions of the program, leaving only parts that are not GPL’ed.”

Developer managers should also make certain that any code written by contractors does not fall under the GPL. Loundy once represented a client who had to rewrite an entire section of its software because the contractor it had used had employed GPL code.

“You want to know the pedigree of whatever intellectual property you’re using,” Loundy said. “Good advice, no matter what software you’re using or who you’re hiring, is know who created what and what rights come with it.”

Know what you’re agreeing to
Jennifer Hopkins, an attorney for the law firm Orr and Reno in Concord, NH, was not familiar with the GPL, but she does work with open source contracts. She said she’s frequently bailing out clients who call for her advice after they’ve already signed a license or tagged a license onto their product.

In general, she said, companies should be careful about generic licenses that aren’t written for their specific needs. Companies can avoid a lot of trouble by calling their attorneys to review licenses first.

“I tell clients the time to call me is before you sign the license or before you create the license, and usually what I see is people calling when they have a problem that comes up down the road,” she said. “The license might be the best asset you have. You have to make sure it really does what you want it to do.”

Denying liability doesn’t make it so
Hopkins also raised the issue of the liability of releasing software with potential problems under any license. Although the GPL, like many other free and open source licenses, clearly warns that there’s no warranty, Hopkins said that doesn’t mean you can’t be held accountable if you release something that the courts deem reckless or dangerous.

“Just saying it doesn’t make it so,” she said. “I can see there may come a time when somebody tries to get behind a license or go around it and say, ‘Yeah, I know you said no warranties, but this was such a bad result that it’s really against everything we know about delivering something to the public.’”

Confusion over what’s actually free
If anybody can attest to the benefits of GPL, it’s Marten Mickos, CEO of MySQL. The Swedish company uses the GPL for its popular database and has parlayed the license into a successful business model, selling support, customization, and relicensing for companies interested in incorporating the database into a proprietary solution.

While Mickos said the license has worked well for MySQL, he acknowledged that there have been problems with people confusing free use of the product with free use of the trademark name.

“The GPL does not explicitly say that the free use does not include the right to use the trademark of the product in question, and not all our GPL users understand this,” he said. “What we mean is that some organizations who use MySQL under GPL believe that they can use the name ‘MySQL’ absolutely freely and put it in their own product names.”

He also noted that because the GPL does not deal with software leases used by ISPs and ASPs, these organizations are sometimes charging their customers for use of GPL software without paying the original author any fees.

Proceed with caution
The bottom line, according to Hopkins, is to make sure that whatever license you use meets your business needs.

“I would steer a client more toward analysis of the business goals and whether open code license can meet that,” she said. Nearly any business model will work; you simply need to determine what best fits your goals.

Licenses, good and bad

Have you been in a situation where having the right license was an asset to your company? Has a software license of some type caused you more headache than it was worth? Send us an e-mail with your experiences and suggestions or post a comment below.