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You could make something like this with HTML, CSS, JavaScript and NodeJS (which is just JavaScript).
HTML and CSS to build the pages and style them to make them look nice.
JavaScript to power "events" - for instance doing something when a user clicks a button.
NodeJS runs on a server and lets the users view the different pages and fills them with information from a database.
For the database you'd probably want MySQL, this also runs on the sever so your NodeJS backend can get all the information it needs.
There's other things to consider as well, frameworks to make creating the website better (e.g. React, AngularJS, etc). But honestly, you're better off making something much more simple first. Forums and stuff are pretty complicated to build - especially alone. So you want to take baby steps.
Answers
it was made with html and with javascript or css
press ctrl + shift + i
to know better how this I forum was made...^_^