I would say that instead of spending a lot of time on a conceptually different language it could be more beneficial to study, say, distributed algorithms or software/system architecture principles or your business domain. There is so much knowledge in this world that learning how to code the same thing in, roughly speaking, one more syntax seems like a waste of time. Even paying real attention to what is going on in the cloud computing can easily consume most of one’s spare time.

From a real life perspective, it takes years or working on nontrivial software to master a language. For example, some people still manage to have only a vague idea of util.concurent – and this is just a small enough (and well explained in the literature) part of Java. How realistic is it to expect that the majority of developers will be able to master multiple languages concurrently? And who wants to maintain a code base written in widely different languages? Which most likely means multiple IDEs, unit testing frameworks, build systems (hey, not everyone is using even Maven yet), innumerable frameworks etc. And most of the interpreted languages among those are not even likely to run in the same VM. Not to mention the number of jobs asking for non-C++/Java skills.

Curiously enough, this argumentation is hardly ever mentioned. Authors tend to assume that developers are lazy or have nothing else to learn.

Personally, I am planning to look at Scala and probably Erlang but even judging from the number of books on those it’s clear to me that they represent merely a niche market. Frankly, I wish they had not cut as much from C++ to “invent” Java. If we had operator overloading/real templates/STL in Java I say we would be able to use quasi-functional designs without going for one more language.

I am sorry if it sounds like rant, it’s just quite a personal thing for me :)