Hi,

so at first glance, one can see that the Cosmos team is also involved in Plasma, see the Plasma implementers calls starting here: https://www.youtube.com/watch?v=_DPftmg7zR8

There are 5 devs from Cosmos/Tendermint. The loom guys have joined in call #10, see here:
https://www.youtube.com/watch?v=M_PtvXrrTko

Plasma is still in a very early development phase and things might change, however one important difference is that Plasma is a second layer solution, where a base/mother/1st layer chain supports many 2nd layer chains. On the first layer there are smart contracts that are used to proof that everything on the 2nd layer is going well. So there is a hierarchy, which allows scaling of ethereum, without changing ethereum itself, it just becomes the 1st layer and then the 2nd layer is added which gives a lot of throughput.

In Cosmos though, there is no clear hierarchy. Things arrange as they are connected. Right now there is the Cosmos Hub, the first hub of the Cosmos, but there is also the IRIS Hub, a bit different approach but quite similar. In the future there might be other hubs and these hubs are connected and zones are connected to the hub, which actually offer the functionality that users are seeking. For example cryptokitties would be put into such a zone. So the topology of this network is quite different, since it is not necessarily a star topology, it becomes whatever topology the developers deploy and how the hubs and zones interconnect. This might be the reason why Cosmos calls itself “internet of blockchains”. I hope that helps.