Test Automation for Internet Explorer
* UPDATE Feb 2020 *
Cypress is a new tool for browser testing and one of the few tools that doesn't use Selenium under the hood. It does NOT, however, support Internet Explorer. It does support Microsoft Edge and many other modern browsers, so hopefully it helps some people.
* UPDATE (older) *
Selenium Web Driver is the successor to Selenium RC.
So the answer is still to use Selenium in some form. That could be any of the supported frameworks.
Personally I'd use Protractor (useful for more than just Angular apps) or Leadfoot (from the Intern.io project).
* ORIGINAL RECOMMENDATION *
If you're already using Selenium, I'd use Selenium Remote Control
You can still use selenium for IE Explorer. I don't know if there is a plugin, but that shouldn't stop you. You'll get a lot of benifit from using the same tool to test on all browsers, so I would think you would be better served to learn how to use selenium with IE Explorer rather than trying to re-implement all your tests in another tool