"Is it really something about Ruby-the-language or JS-the-language that made them so compelling?" Well... It obviously depends on a person. What is compelling

"Is it really something about Ruby-the-language or JS-the-language that made them so compelling?" Well... It obviously depends on a person. What is compelling to you may not be so for me and the other way around. And in this instance it depends on what you know already. So, in other words, are JS and Ruby compelling to someone who learned Pascal or C in school and writes PHP for a living? Hell yes! Are they going to make him a better developer? There's a high chance they will. Ruby sports an object system that is somewhat similar to Smalltalk, with many idioms borrowed from it. That's completely different Object Orientation and learning it can have benefits. If nothing more, it gives you another way of modeling problem domains, which is always a good thing. JavaScript was an objective-functional mesh long before Scala. Coming from C or PHP, seeing first class functions with implicit state (closures) can open your eyes for yet another way of modeling things. Building, in essence, your own object system when you use a language is a valuable experience, too. Different languages have different semantics and knowing many of them helps in expressing yourself. I hear that what we think is constrained by the language we know. That's true for programming languages too.