Selenium or Eggplant [closed]

The Automation tools have to have the browser open to truly do the automation tests. It's an actual representation of what the end-user would do (clicks, changing URL, clicking browser [BACK]/[FORWARD] buttons, key-presses, etc..), so it must launch an instance of the browser. Selenium IDE can only run in Mozilla Firefox, but if you set up Selenium Remote Control server, and choose a client (NUnit using .NET, JUnit using Java, etc..) and launch your browser from Visual Studio (using NUnit) or from Eclipse (using JUnit), then you can test your script in multiple browsers. They also have Web Driver which is a newer way architecture than Selenium RC (Remote Control).

I've never used Eggplant, so I can't criticize on it.

As for the things you had issues with during your proof of concept, I can help you with those. Selenium is actually JavaScript running on top of any JavaScript running on your page (ie: AJAX in your case), so it will work fine for those situations. Can you describe the behavior of the StaleReference Exceptions?

I am using Selenium and Webdriver. In ChromeDriver, the browser can actually run in background (verified by myself :) )

So I would suggest Selenium - and moreover, you can find support here ;)