Work on GPL Version 3 continues, but the debate between Richard Stallman and Linus Torvalds over new features is less important than the rewriting of the rules that GPL has imposed on the landscape.Since its inception in 1989, the GPL has stared down know-it-all arguments that it will never work, that it's contrary to free enterprise and that it denies software creators the rights to their intellectual property.

Instead, it has proven a sound basis on which to found a company. Both MySQL AG and the former JBoss Inc., now a unit of Red Hat, have successfully made use of the license.

Both have illustrated that a software company issuing its product under the GPL could take on value faster than a proprietary software firm. Granted, both MySQL and JBoss reserved the right to sell the same software under a commercial license-they maintained clear title to the code-and the commercial license granted the user certain proprietary rights. But most copies of JBoss and MySQL gained their wide adoption under the GPL-or Lesser GPL in JBoss' case. That's a variation that keeps the code open source but allows you to use it internally bundled with your own in-house systems or proprietary software without the giveback provision kicking in.

How can a company be based on a license that requires the firm to give away its source code to anyone who seeks it, including the competition?

Matt Asay, the outspoken VP of business development at Alfresco, is the best person to answer the question. The Alfresco content management system recently moved from the Mozilla license to the GPL "because the GPL is very effective against competitors."

If a competitor takes your code, modifies it and redistributes it, then the giveback provision reasserts itself. It's only Lesser GPL code that's combined with proprietary code for internal use that gets the exemption. So your competitor will be required to give the originating company all the changes that its made.

And the community that's formed around the original GPL code will probably not assist the competitor with further improvements. But it will quickly assimilate a competitor's changes, test them, modify and expand them and in general make life miserable for the competitor.

"With the GPL, you get the value of the changes back. You don't get that with other licenses," Asay notes. And if the original code supplier is on the ball, its going to move faster than any competitor can keep up.

"It's produced the best open source companies on the planet-Red Hat, MySQL and JBoss. The GPL is best suited for commercial companies. It's all about beating up our competitors…" he says.

But more profoundly, the GPL enables a fundamental change between a software company and its customers that in the long run is going to give GPL companies immense staying power.

"The GPL aligns the company's interest with the customer's. It forces me to stop thinking of the relationship as ending when I ship a set of bits. Instead, that's the start," and the nature of the ongoing relationship is determined by the caliber of upgrades to those bits, the quality of technical support, the strength of the programming community that forms around the bits.

The GPL "changes the relationship with the customer and changes it in a strong way. Now when we go out to sell our product, our product is our company," and not a shrink wrap software package, Asay said. One of the great ironies of the GPL 17 years after its creation is that is has become an unabashed creator of companies that compete effectively. If its critics are feeling the heat, let them explain why.