Linux

tmsu is pretty cool - it creates a little db and uses that to track tags on your files without ever touching them. It also has it's own little tag based filesystem.

find?

+1 to caddy. There are some services that set safe headers following the recommendations outlined by Mozilla but others don't control headers as strictly. Caddy is the only web server that I found that supports loose default header values. These values will be selected unless the upstream application specifies their own values.

You can do something similar in nginx but it requires playing with maps and has a little more indirection than I'd like.

Just wish caddy was capable of starting as root and stepping down permissions like Nginx. I have certs being managed by other tools and have to make sure they are installed and chowned for caddy's use when they are cycled.

People always sleep on script. It's badass and let's you do goofy things like this while keeping standard terminal formatting: https://github.com/StaticRocket/dotfiles/blob/043e9a56cc9515060188ec4642e4048c0dd6c000/dot_bashrc#L79-L94

motion

After spending years dealing with shady freeware and junk software on windows, I was floored by how easy and nonchalantly I was able to set up a simple security camera on my PC

Idk a lot of commands but I think wget for downloading webpages and rsync for syncing devices are pretty awesome

Inshellisense is teaching me a lot. :) It's an autocompleter.

https://github.com/microsoft/inshellisense

Also, Atuin for history.

https://github.com/atuinsh/atuin

Underrated or not widely known?

I love lazygit and I'm still surprised at how many people are shocked when they see it for the first time. Not exactly a command, but a very handy text UI tool.

For more elementary tools, I can't believe how many people know about ! and ctrl+r who don't also know about fc and edit-and-execute-command.

Underrated

Both linked projects have over 60k+ stars on GitHub

Pick one

As someone who has to do installs and admin at work a lot I'm constantly dealing with yum/dnf. I cry when I have to work with AIX.