What is the best way to write a server for a Real-time browser game?

Question

Web development

I decided to fulfill my childhood dream, to write a browser game FOR MYSELF . Thus, to learn something.
Although I have experience in programming in different languages, it does not apply to servers.
I wanted to ask about the best language and framework for writing a server based on my current "knowledge" . So that I learn something new, but do not learn a new language from scratch. And used already mastered.
The server should be productive, because in theory it should perform a lot of calculations and exchange between players in real time.
Here is a list of my "knowledge":

• C++ - Good level, no experience writing servers. But the soul lies with him.
  
• PHP - Good level, but sick.
  
• JavaScript - Good level. I even used Socket.io for certain work tasks. As I understand it, you need to use Node.js
  
• Java is weak. I know the syntax and "philosophy of the language", but wrote little
  
• C#, ADO.NET, WCF.NET - Intermediate. He wrote back in his student years. I know the language well, I wrote a server-client application, about 20k lines
  

I would like to hear comments about each of the above languages ​​and frameworks suitable for my needs.
UPD: I also wanted to know what frameworks you use and for what tasks. Can you tell me the most convenient for my purposes

Answer 1

Choose any ... everything will be more than pulled!

Answer 2

All the mentioned languages ​​\u200b\u200bare suitable for yourself, there are enough tools for any choice