For the past year I’ve been raving about Node.js, so I cracked a huge smile when I saw this question on Quora:

In five years, which language is likely to be most prominent, Node.js, Python, or Ruby, and why?

For months I had been repeating the same answer to friends: “Node.js hands down. If you want to build great web apps, you don’t have a choice, you have to master Javascript. Why then master two languages when you don’t need to?”

Javascript+Node.js is to Python and Ruby what the iPhone is to MP3 players–it has made them redundant. You don’t need them anymore.

So I started writing this out and expanding upon it. As I’m doing this, a little voice in my head was telling me something wasn’t right. And then I realized: despite reading Taleb’s books every year, I was making the exact mistake he warns about. I was predicting the future without remembering that the future is dominated not by the predictable, but by the unpredictable, the Black Swans.

And sure enough, as soon as I started to imagine some Black Swans, I grew less confident in my prediction. I realized all it would take would be for one or two browser vendors to start supporting Python or Ruby or language X in the browser to potentially disrupt Node.js’ major advantage. I don’t think that’s likely, but it’s the type of low probability event that could have a huge impact.

When I started to think about it, I realized it was quite easy to imagine Black Swans. Imagine visiting hackernews in 2013 and seeing any one of these headlines:

Microsoft Open Sources Windows.

Researchers Crack SSL. Render it useless.

Google Perfects Voice Recognition.

Facebook Covers the World in Free Wifi

Amazon Launches Distributed Data Centers in your Home

It took only a few minutes to imagine a few of these things. Clearly there are hundreds of thousands of low probability events that could come from established companies or startups that could shift the whole industry.

The future is impossible to predict accurately.

All that being said, Node.js kicks ass today(the Javascript thing, the community, the speed, the packages, the fact I don’t need a separate web server anymore…it is awesome), and I would not be surprised if Javascript becomes 10-100x bigger in the years ahead, while I can’t say the same about other languages. And if Javascript doesn’t become that big, worst case is it’s still a very powerful language and you’ll benefit a lot from focusing on it.