Kusama (KSM)

Self-described as "Polkadot's wild cousin," Kusama is an experimental blockchain platform that is designed to provide a massively interoperable and scalable framework for developers.
Kusama is built on Substrate — a blockchain building kit developed by Parity Technologies. Kusama has almost the same codebase as Polkadot — one of the most successful interoperable blockchains.
By deploying on Kusama, fast-paced projects gain access to a highly scalable, interoperable sharded network, with features that are not yet available on Polkadot. To that end, Kusama describes itself as a “canary network.”
The platform is designed to provide a testbed for developers looking to innovate and deploy their own blockchain and can be used as a preparatory network before launching on Polkadot — though many projects opt to stick with Kusama for their final product.
Kusama benefits from a low barrier to entry for deploying parachains, low bond requirements for validators, and is most commonly used by early-stage startups and for experimentation.