What do you mean powered by C++?
The pages themselves are, of course, written in html, Javascript, and css, but generation of math problems, presentation of solutions, and answer checking is done by programs compiled from C++ source code. Server side data management was also done using C++.
If you have opinions about my html, css and javascript you had better keep it to yourself. I write ugly html, Javascript and css, but that's ok since these languages Actually, html is well structered and logical. But it's not a programming language. It's a markup language. But Javascript ... ah hell, Javascript is ok too: I shouldn't talk so much smack. In fact I like the C-style syntax. It's just got some things that are a little weird to me. But now css, that's not programming. That's not even typesetting. CSS IS VOODOO! are already ugly. My C++ sources are, on the other hand, works of art, but you don't have access to those 😜