What is it?

Three common ways are add more perpendicular dimensions, curve space spherically, or curve space hyperbolically. In theory there are infinitely many ways space could be structured and behave. Non-parallel dimensions is another not even done thing.

Why?

It generally is different from what we have in our universe and therefore has different and possibly beneficial uses. For example you can explore many different rooms by just moving in circles in your physical space which uses less of your space while keeping vastness.

Where is it?

CodeParade on YouTube, hackerPoet (same guy) on GitHub, his hyper engine and engine4d are open source. Also, see Steam, or Itch.io for 4d, 5d, 6d, or Hyperbolica. I made my own sort of working any dimensional thing, StinomXE, free and open source.

So what would you do with weird space graphics? X E.