What would a business gain by contributing to open source? If you thought it was hard to gauge the return on investment of hardware or software purchases, try to get your head around the open source question. Whether you"re contributing capital or human resources, it can be difficult to justify an endeavor that, truth be told, could ultimately benefit your competitors as much as your own company.

There"s a persistent idea out there that open source is about philanthropy -- and certainly, many developers are happy to give away code. But for commercial organizations, participating in open source needn"t be seen as a charity project. The long-term benefits can be significant, even if the immediate gains aren"t always obvious.

Take Google, for example. It"s no secret that Google has benefited immeasurably from open source. Its search cluster is built from thousands of Linux boxes. The cost savings alone, compared to licensing fees for Unix or Windows servers, must be tremendous.

Does that mean Google can rest on its laurels? No way. With competitors such as Amazon.com and Microsoft circling in the waters, I can"t think of a segment of the IT industry more competitive than search. So why would one of today"s most closely watched companies spend untold thousands on open source projects, especially when it can"t even be sure those projects will advance its business in any way?

Yet that"s exactly what Google is doing. On June 1, Google announced an initiative it calls the Summer of Code. The rules are simple: Any registered participant who successfully completes work on an open source project by Sept. 1 will earn a stipend of US$4,500.

Is it a cynical ploy? A way for Google to get its odd coding jobs done on the cheap? Not at all.

Not only is Google letting participants pick their own projects -- they can work on literally anything, from office applications, to scientific software, to VOIP -- but the search giant has turned control of the program over to other organizations. It is relying on partnerships with existing open source "mentoring organizations," including such notables as the Free Software Foundation, the Mono Project, and Ubuntu Linux.

Perhaps strangest of all, Google makes no claims on any code the participants produce. It will be truly open source. All projects must be released under a qualified open source license, but the copyrights are retained by either the author or the participating mentoring organization, depending on the organization"s usual practice.

So why do it? What does Google stand to gain? The answer is, potentially, a lot.

When all is said and done, Google is a software company. And software companies need programmers. By fostering interest in software development among students -- and remember, Summer of Code participants needn"t be computer science majors; they might just as easily be budding biologists or civil engineers -- Google helps to ensure a healthy computing ecosystem, which will continue to generate new, talented coders.

Besides, if Google doesn"t benefit directly from all the participants" projects, so what? It might benefit directly from some of them, if not now, then in the future. Think of the Summer of Code as a mutual fund: It"s designed to pay off in the long term.

That"s the key for other companies considering participating in open source as well. Return on investment is important, but resist the temptation to focus solely on short-term gains. The community aspect is what makes open source unique, and what benefits the community ultimately lifts all boats.