You can also run on testnet3 with other full-node implementations, such as +btcd+ (written in Go) and +bcoin+ (written in JavaScript), to experiment and learn in other programming languages and frameworks.
In early 2017, testnet3 supports all the features of mainnet, including Segregated Witness (see <<segwit>>). Therefore, testnet3 can also be used to test Segregated Witness features.((("", startref="testnet09")))
In 2021, testnet3 supports all the features of mainnet, including Segregated Witness (see <<segwit>>). Therefore, testnet3 can also be used to test Segregated Witness features.((("", startref="testnet09")))