A tiny port-forwarder written in golang.
# build and forward from high-http to http on local machine go build ./frwd :8080 127.0.0.1:80
To give you access to ports that would otherwise be hidden or require some work to access.
I wrote this when moving containers from Docker to LXD and noticing that LXD was missing an EXPOSE command. The alternative to using frwd would have been be a cryptic iptables command that would require root access.
As it is with most things in networking, you can already do it with netcat:
netcat -L 127.0.0.1:80 -p 8080
I throw a dart on the Wikipedia FOSS license page and it landed on zlib v0.7