grml - Bootable Debian Live CD with powerful CLI tools. (Source Code) GPL-3.0Shell
mitmproxy - A Python tool used for intercepting, viewing and modifying network traffic. Invaluable in troubleshooting certain problems. (Source Code) MITPython
mtr - Network utility that combines traceroute and ping. (Source Code) GPL-2.0C
Sysdig - Capture system state and activity from a running Linux instance, then save, filter and analyze. (Source Code) Apache-2.0Docker/Lua/C