Cosmos is designed for communication between chains, seeking to improve the stability between them. In short, it is an Internet of Blockchains where all of them can be interconnected.
The open source tools it uses are the following:
Tendermint: It serves to save the network and consensus layers, to reduce creation time in chains.
Cosmos SDK: To simplify the process of creating application in blockchain for more security.
IBC: Interblockchain communication protocol.
It is a project in development that will really facilitate the blockchain but it still needs to fix certain failures in terms of security and as it is still in development it is not convenient to trust a lot but it is still a good idea that may have a promising future.