I've already addressed frontend technologies like HTML and CSS in this series. In the backend you're free to use whatever technology you want to use, it only has to be available for the platform you're working on. And even that is no restriction, since you can also choose your complete server stack as you want. It does not affect the user. You can write your backend code in 68K Assembler and run it on such a chip, if you want. The only common characteristic the system has to have is to speak the IP / TCP / HTTP protocol stack to deliver the content to web clients. Therefore, there are many different backend technologies, some newer, some older, with different philosophies and communities of different sizes and compositions.