IOTA tangle visualization
Look at this beautiful visualization of IOTA network. It is live here. The nodes are individual transactions, every node is connected to two other nodes in the network. There are no miners, if you want to create a transaction, you have to do some mini proof of work - confirm two of the previous transactions. No miners = no blocks, no fees.
Credits for the visualization go to https://forum.iota.org/u/glumb