Stellar XLM: Testnet Launch

By April 1, Stellar plans to launch the first elements the technology on a test network, with ambitious plans to release an implementation for real payments by autumn.

A testnet is an alternative cryptocurrency blockchain, to be used for testing. Testnet coins are separate and distinct from real coins, and are not supposed to have any value. This allows application developers to experiment without resorting to using real coins and not worrying about the integrity and security of the mainnet.