netcat 1.1.0

Netcat is a simple Unix utility which reads and writes data across network connections, using TCP or UDP protocol. It is designed to be a reliable "back-end" tool that can be used directly or easily driven by other programs and scripts.

At the same time, it is a feature-rich network debugging and exploration tool, since it can create almost any kind of connection you would need and has several interesting built-in capabilities.

Perhaps some equivalent to netcat, or "nc" should have been written and distributed ten years earlier as another one of those cryptic but fundamental Unix tools that we all use daily without even thinking about it.