Selenium IDE on Firefox 4 is Available for Testing! Now! There have been a lot of questions about the support for Firefox 4 in Selenium IDE. We know that the current Selenium IDE v1.0.10 does not support Firefox 4. It is not a simple matter of bumping the maxversion to make it compatible. There are core technical changes that make the existing Selenium IDE incompatible. So, Selenium IDE v1.0.10 wi