I was around at the dawn of personal home computing and for the commercialization of internet technology so I have seen each of these come and go. Though they a

I was around at the dawn of personal home computing and for the commercialization of internet technology so I have seen each of these come and go. Though they are not the cool kids anymore, the sheer volume of code keeps them around, and given that people have those skill-sets, new code gets produced in them. Java was certainly the fad dejure in it's time, OO was the craze and Java had just been dumped out on the internet, by Sun, for free. In a time when a good portion of compilers costed money (especially if you where not on an Intel based PC), you could learn Java for the price of an internet connection. c# was the cool kid if you where a Windows developer, Microsoft was looking to update their aging development stack and give themselves hardware portability, so they basically created the JVM for windows in the form of .NET . To ensure that people switched over they kicked the legs out of VB6 and pretty much forced everyone to the new dev stack. They offered a host of language that you could use to write windows apps, but they conformed all of them to the OO style that was popular at the time. With that said, VB.NET did not look like VB6 it looked a whole lot more like C# with VB syntax. So given that developers had to pretty much learn a new language even if it had familiar syntax most opted to just go ahead and learn c# as Microsoft was pimping c#. Python is the odd ball in your list as it kind of languished for a while. It was not obscure but it was more like Ruby, it had it's devotees but was rather flat, not obscure just flat. That being said, it did have it's cool kid, day in the sun and that was when Google started using it heavily. The AI winter really killed LISP as "the" AI language and there really was no heir apparent, that is until (IIRC) Google started producing some of their machine learning tech and they implemented it in Python. This instantly made Python the cool kid and people started adopting it. My opinion is that Google felt they where too heavily invested in Java and thus needed to diversify into another language. At the time there where not a lot of options that had the combination of mature enough/without legacy clutter/availability of developers, to make the cut, that is why I think Python made the short list. TLDR: the GP poster is right, popularity and trends have more to do with language adoption than technical merit does.