Everipedia is a crowdsourced link, comment, and knowledge aggregator.
Background
Wikipedia has a limited number of contributors and topics. I once tried to create my own Wikipedia entry and got denied. Everipedia allows anyone to contribute and anyone to have their own page. It's much more inclusive than every content aggregation platform that has come before it.
Why would you want to use it?
Learn information about anyone, or create your own page for anyone or anything.
I think the one thing that it's missing right now is incentives for contributors. Right now, people are contributing out of altruism or their own personal interest. Earning something of monetary value (e.g. STEEM) would be a great way to create more engagement on the platform.