asdf is a tool version manager. All tool version definitions are contained within one file (.tool-versions) which you can check in to your project's Git repository to share with your team, ensuring everyone is using the exact same versions of tools.
Alternative plus évoluée à netcat : ncat
via ArnaudB
Swaks is a featureful, flexible, scriptable, transaction-oriented SMTP test tool written and maintained by John Jetmore.