I don’t understand a lot of this discussion considering Google in general. @federico, business does have golden rules and marketing, public perception, and company image are all very high on the golden rule list. I do believe Google does do things “just” for the user without a very short term measurable ($.15 per click) value. But the long term indirect value must be measured.

It’s very short sighted to think Google would try and “slip one by” it’s users in some of the methods previously posted. It would have detrimental effects to their company. Web developers, the source of their money, would jump ship, FAST. They know we are the ones that use Google products, code Google Adwords for programs and sites, recommend search engines to friends, and generate “buzz.”

The other more philanthropist reason for doing this is as mentioned the over all load on the internet. As Ben said making a significant contribution to this would require a company the size of Google. The fact that they make so much money means that they can afford to dedicate employees to projects like this. And why not?

Think of the AJAX API team as an extension of the marketing department with real benefits.

Question arose…why your team sat down and brainstormed how you could solve existing problems on the web?

I mean, important question is not “Why does Google host these libraries?”, instead, why google want to help us? what did they gain?

As a profit-based company they must get something in exchange. That’s a business golden rule and I dont think google is the exception.

Sorry to be so distrustful but I just simply don’t get it.

- Why does Google host these libraries?
The AJAX Libraries API came about because our team sat down and brainstormed how we could solve existing problems on the web that can only be solved by large companies such as Google — one of those problems is that the same bits from a few popular libraries are being grabbed millions and millions of times a day and it’s unnecessary.  Google is uniquely positioned to serve large amounts of traffic from around the world at the fastest speeds so we decided that creating this API could help other sites as well as our own.

- Is Google using the referrer/IP for tracking users?
No.  The API is not a devious plot to track users. Our intention was to help speed up the web and help with some of the chaos that we see in the wild. There are still plenty of sites that are not setting correct cache headers to minimize latency and don’t have the global deployment to ensure that users visiting from Europe see the same low latencies as those on the west coast of the US.

With that said, we do have logs of referrers, IPs, and user-agents. There is no user tracking, and these logs are subject to our 9 month anonymization policy (details at http://www.google.com/privacy.html). Our team uses these logs to understand the performance, adoption, and status of the system. These signals are used by us mainly for capacity planning purposes. Since we launched the API last year, we have expanded some of our operations and grown our capacity. The signals we get from these logs are directly responsible for our ability to meet the needs of the community and help ensure global, low latency access to the system.

- Why are we hosting SWFObject?
We host the most popular libraries because the caching benefits are greatest (more sites using them through Google means users are more likely to have it in their cache) and SWFObject is one of these popular libraries.

Additionally, SWFObject is hosted on our Open Source Code hosting, http://code.google.com/p.  It became a very popular library and developers started including the Javascript directly from code.google.com.  Our code hosting servers were meant to host code for development purposes, not as production servers.  We contacted the creators of SWFObject and asked them to direct users to the AJAX Libraries API which has production servers meant to handle the high load.

- Does Google insert code into the libraries?  Will they?
Absolutely not.  We refuse to make any changes, trivial or not, to any of the libraries we host.  You can verify this by downloading the libraries from us and the maintainers and do an MD5 checksum on them.
http://www.prototypejs.org/assets/2008/1/25/prototype-1.6.0.2.js
http://ajax.googleapis.com/ajax/libs/prototype/1.6.0.2/prototype.js

- What does the /stats request do?
Because many loads of the libraries are cached, we never see requests for them.  In order to better estimate our traffic, we use this request to inform us what has been loaded. Also, the request happens asynchronously much after the page loads so that we don’t slow down the application performance.  If you don’t want these requests to happen, you can include the libraries directly instead of through the loader.  The direct links are all listed here:
http://code.google.com/apis/ajaxlibs/documentation/#AjaxLibraries

The reason they are a good thing as a webmaster is that if many sites use these the libraries will get cached in the users browser at some point and then when he goes to another site using the google libraries he doesn’t have to load them up again.

You have to admit, even without attributing any malice or power issues to Google, that their central code repository will be an attractive target to someone wishing to cause mayhem on the web.

As for why they are doing it? It’s a cheap service that makes their own development efforts easier, and they get the bonus of being able to track (with more or less precision depending on the method used to include the libs) who is using what. They can focus their own efforts to provide better hooks and services to the devs who are using the big three libs.