I've been exploring hypergraphs a lot over the last 12 months. They are an incredibly rich way to look at a lot of existing (and new) mathematics, so much so that I think hypergraphs will have a good chance to become a signature mathematical structure over the next 100 years.
Unfortunately people don't yet have a good notion (or notation) for what a hypergraph even is! The wikipedia page is a disaster area, for example. Partly this is due to a lack of careful, general groundwork on how to think about hypergraphs. I'm confident this will get done though -- and aim to play a role in that. My personal view is that you need you really need to adopt an ADT-type viewpoint to do this, but I'll have to leave it at that for now.