This is a really odd way to approach programming languages, I feel. According to the article, none of these are very mainstream languages (although certainly scheme and clojure have their adherents, and LUA is used extensively in the game industry), but they should be watched because of hiring trends?<p>I'd much rather pick up a language because it has some interesting features, or because it solves a problem I have with one of the languages I already know. Seems they're missing the forest for the trees, somehow.