Command-line client for WebSockets, like netcat (or curl)
The all-in-one Red Team extension for Web Pentesters
PHP library for printing to ESC/POS-compatible thermal printers
For full, incremental, compressed and encrypted backups or archives
Directly 'cat' into the link layer of a network...
netcat for bluetooth!
netcat -C ip port same as netcat -L -p port
Perl Hacking Tools (BackTrack)
BlackBSD
Perl GUI for DD with netcat / cryptcat support