Google is a for-profit company, so I'm pretty sure they don't adhere to the same open-source spirit that drives Drupal and other such open-source projects. They are correct in their postulation that open-source is the way to stay light and speedy, but they still gotta make a buck... I'm sure they won't be giving up ALL of their knowledge anytime soon...

Google certainly doesn't give out all of their discoveries and code; but they do make quite a few things "open" in one sense or another.....

They frequently use open standards, which makes it vastly easier for people to re-use or interoperate: respecting the usual robots.txt is one example; Google Books putting their scans in PDF and their full-texts into Open eBook format (eventually -- only some of them so far) is another. And as far as their "secret sauce" web-indexing technology, they publish in the normal journals and share the general approach, even though they don't give away everything.

And on the flip side, they don't freely give out search logs or other information that would likely put privacy at risk -- that seems to me a good thing even though i'ts specifically not "open".

Also, Google Books seems pretty cool about letting people re-use the scans and full-text they're producing (at a prodigious rate, I might ad). It would be pretty tacky to claim copyright in a simple scan or OCR of a centuries-old book, but many others have made such claims; so it's nice to see Google following their "don't be evil" motto.

So yes, they're a commercial company and they keep some stuff close; but overall I'd say they're a pretty good open-source citizen.

I agree, Steve... Google seems to strike a healthy balance. I don't know much about Google Books, but plan on checking it out now!