Leaving aside if X tool/language is open/closed source, expensive or not, the "beautifulness" of the language, etc., also performance not being such an important issue, and focusing only on what technologies (IDE + language + resources + frameworks + community size, etc.), are known for allowing programmers in the most quicker way to put ideas for a web app online.
I mean, there are different focuses on different technologies, which technologies are the most RAD oriented for web apps?