Shadowsocks is a free and open-source encryption protocol project, widely used in mainland China to circumvent Internet censorship. It was created in 2012 by a Chinese programmer named "clowwindy", and multiple implementations of the protocol have been made available since. Shadowsocks is not a proxy on its own, but typically, the client software will connect to a third party socks5 proxy, speaking the shadowsocks language on the machine it is running on, which internet traffic can then be directed towards, similarly to an SSH tunnel. Unlike an SSH tunnel, shadowsocks can also proxy UDP traffic.