How can I make a .io game ?

Question

Should I learn a specific language ,and which game engine I need for that?

Answer 1

finally some one here asked about io games. they are my favorite and it has always been my dream to make one. io games are multiplayer so they need knowledge of back-end (servers and stuff). the client is usually written in js. for the server side you can use anything from nodejs to c++.
> agar.io was written in c++ and js.
> diep.io was written completely in c++.
> zombsroyale.io was made in unity.
most of the io games are written from scratch meaning that they dont use any third party game engine. but there are some which had been able to gain huge player count being made using some 3rd party engine.
here's my github, i made some for fun. they aren't great and couldn't really yield any money.
for io games to run with low ping, you need to purchase expensive servers that actually cost a lot. Matheus Valaderus (the agar.io guy) paid $15k per month to keep the servers alive.

Answer 2

github.com/bytezeroseven
edit: for real time communication b/w the server and the client, io games use websockets.
edit2: i am not proud of my old projects as i made them when i didnt have much experience and hard coded everything. so i suggest you check the latest ones. eg single player diep clone: (left it incomplete)
https://github.com/bytezeroseven/diep22