PLURALSIGHT.NET.AUTOMATED.WEB.TESTING.WITH.SELENIUM-JWARE

I am comparatively new to selenium and played a little with selenium IDE, and trying to do with selenium rc. I am baffled to use the scripting language there. Can you tell me what is the most used language in selenium across industries? And also I came across this course http://www.wiziq.com/course/12451-selenium-automated-web-browser-testing-for-web-applications os selenium automated web browser testing is this good? If someone does in Java and he joins a company where everyone does in ruby, then it’ll be a pain to learn ruby again. And also it would be great if you address any comparison about the available languages like (perl, python, ruby, java etc.) or tell me any other guidance would really appreciate help and also i would like to thank for all the information you are providing.