This was a project made in C++ using OpenGL, this project, although still unfinished, is an attempt at recreating the popular platform shadertoy in C++ using OpenGL.
Shadertoy is a platform allowing users to easily write standalone shaders in GLSL (OpenGL Shading Language).
This is the effect that is been rendered in the background of this webpage, but higher quality. And yes, what you're seeing when opening this page is not a fancy CSS effect but an actual shader effect :)
As you can see in this example, my program allows you to fetch the mouse position from the shader and do whatever you want with it.