Why do you want to do headless testing? Is it purely due to the environment (such as I want to be able to run some automated tests on a build server that does not have a graphical subsystem)?
While not having a list of tools available for these engines, consider the tools that use the following engines if your target environment are in these browsers:
- IE9 - Chakra
- Safari - WebKit
For testing these engines, I prefer to use the browser using Selenium.