What tools/sources can be used to predict the next big languages and toolsets?
As an example, if I wanted to compare the prospective future of Node.js+Express.js against Ruby+Rails, where could I look?
So far, these sources come to mind:
Sponsorship and/or adoption by a company. Building out tools and infrastructure for a new language (rather than a new framework) is hard, costly and time consuming.
Google put tonnes of effort into making Eclipse better for J2SE. Ditto Apple for Objective-C. Microsoft doesn't just release languages, it releases entirely new development environments. If you're serious about your toolchains, pick a language with serious corporate backing :)