Are there any publicly available aggregators of client data (user-agent, screen resolution, OS)?

Emphasis on publicly available and aggregate

I'm looking for data similar to stats you'd see for your own site in Google Analytics but for a large chunk of the web:

TOP 10

• Browsers
• Operating Systems
• Screen Resolutions

Perhaps even aggregate statistics for Alexa's Top 10?

I guess a potential benefit here would be to es开发者_StackOverflow中文版tablish which browser/resolution/OS combinations would give the most bang for your time to test for a new site.

http://www.w3counter.com/globalstats.php