> That holds for every mainstream X. It makes the challenge ridiculous. But that was the point... :( Or put another way, the major languages only include the

> That holds for every mainstream X. It makes the challenge ridiculous. But that was the point... :( Or put another way, the major languages only include the "middle of the road", conservative features: mostly safe, uncontroversial, and well-specified and tested (it's all "mostly", "approximately" so, there are obvious exceptions). There is a limited supply of such features, which makes all the major languages have non-trivial amounts of overlap in terms of concepts or implementations. Moreover, even if one language implements a truly unique feature, it gets copied the next day (to where it makes sense), leading to even more similarity between languages. The other part of what I'm saying is that if you research and learn as many unpopular languages as you can today - right now - you'll be covered (in terms of having to learn new features in your job's PL) for at least the next decade without any additional effort.