Bray, who is Director of Web Technologies at Sun Microsystems, co-creator of the XML 1.0 and XML Namespace standards, co-founder of Open-Text, and contributor to the Atom Publishing standard.
Bray outlines the basic advantages of each of these three platforms (or rather the two languages and one framework if you are scoring at home). In perhaps in a nod to his new employer, Sun, Bray totally omits any mention of .NET or smaller products like Adobe’s Flex/ColdFusion platform.
His idea, if you are able to take it on the surface only, is to rate your priorities of: 1) Scalability, 2) Dev Speed, 3) Dev Tools, and 4) Maintainability. In this highly generalized approach, you could theoretically pick your web application building language/framework based on only these priorities.