Tool: sbd
Use: Enumeration and much more.
Version: 1.37
OS: Windows, Linux, MacOSX & others.
Vendor/Author: Michel Blomgren <[email protected]>
URL: Unknown
Status: Unknown/Inactive (Last commit seems to be from 2005)
Description: TCP/IP swiss army knife like Netcat and Ncat.

This tool is very much like Netcat and Ncat and have very similar capabilites. The featureset includes encryption and running as a daemon.
I am not aware of any official download sources except for the Kali Git repository as seems to be archived.