# Rococo: v2.1

Rococo is a testnet runtime with no stability guarantees.

## How to run `rococo-local`

The [Cumulus Tutorial](https://docs.substrate.io/tutorials/v3/cumulus/start-relay/) details building, starting, and testing `rococo-local` and parachains connecting to it.

## How to register a parachain on the Rococo testnet

The [parachain registration process](https://docs.substrate.io/tutorials/v3/cumulus/rococo/) on the public Rococo testnet is also outlined.