The first thing that came to mind when I saw the question is perhaps a bit of a weird answer--but I really want to learn SELinux. It's completely overkill for my Linux desktop and the few services I run on my network. The same with OpenLDAP, I want to play around with it even though I have no real need for it with my setup, I just haven't gotten around to it yet.
On that note, I also feel like I want to learn Ansible, or some other configuration management tool. The thing is, I haven't even played around with it (or any others) enough to really even get what the intended use case is. I'm looking for ways to manage policies and configurations across multiple machines in a common way, but it feels like the more common use case is deploying webapps. So while it's on my list of things I want to learn I don't even have sufficient background at the moment.
Then, finally, the other thing that came to mind was timeshift--or really BTRFS snapshots in general. It would be nice to have that additional feeling of safety while playing around with my systems.
Same, niri. Want to move away from hyprland for so long. Also Emacs but I don't want to spend months configuring.
Also a foss android distro, but I can't find one for this phone.
there are also lots of other things like common lisp, Redox OS, cosmic desktop, trying to make my own compositor, rope science, activity pub, webtransport, bevy, ecs, and much more.
Also I stopped Using Emacs.... because it's very slow
I've been using a mix of Emacs and Neovim and plan to switch completely to Neovim when I have replicated enough of my Emacs config to be comfortable in Neovim. And speed is the main reason why.
Also, qutebrowser. I want to use it but it lacks workspaces support and as a self proclaimed tab hoarder I need my workspaces. I'm also still looking into a pasword manager for it (though I can always just use Bitwarden as an app)
I want to lean back and be immersed on the desktop so bad, but only if it is worth the cost (e.g. not trading ever detail of house in ewal time to Facebook ...).
Neovim. I tried to use it a year ago, but I felt like I was fighting it every time I just wanted to make progress on my project. VSCode doesn't get in my way.
I'm going to give it another shot in a few years.
I want to learn stenography, but haven't really got to buying a keyboard designed for it. I also want to host an EteSync server, but the HTTPS thing has been a bit of a headache for me and I've mostly just left it sitting there.
I've been using Niri with Xwayland-satellite lately, and it works as a charm. it works out of the box, and you simply run it in background, and launch your X programs with DISPLAY=:0
I think a lot of the recent AI tools could be fun as toys to play around with, but I'm just very uncomfortable using tech that exploits everyone who doesn't own a huge megacorp.
Also, emacs as a replacement for my graphical editor. It feels like there isn't a "neovim" style modern version, and there's a steep learning curve to configuring it.
Lapce, an IDE written in Rust. It's nice and light compared to most IDE's, so I use it a bit on my aging laptop from 2015. However, it doesn't have the extension ecosystem or polish of my favored IDE, VS Code.
Bcachefs, and bcachefs on root. Need something with filesystem level encryption instead of LUKS, and *ubuntu's and derivatives have all abandoned ZFS on root installs now.
fish. I think it has most things i want out of the box, so it should be simpler and snappier than my zsh setup. it's just that zsh hasnt bothered me enough to try it yet.
also nushell, im interested in the idea of manipulating structured data instead of unstructured text
Common Lisp. It would take a long while before I'm comfortable working on a project using that language.
There's also Lem editor but setting it up is a pain on NixOS.
Anything beyond setting up a network-wide dns blocker on docker, so... crowdsec, fail2ban, some proxy-related stuff, zero trust tunnelers and so on.
Why? Because its overkill to my current setup and I don't see myself using em for real other than for learning purposes, and thats it.
And before someone asks "Do you protect your server at all?". Other than making some "hacky" stuff with my internet so all ports appear as closed whilst they actually aren't? Eh, not really. Still, my server is about to reach a year of running nonstop 24/7 and it has never been hacked a single time since then, so naaaw.
Elixir, or Gleam/pure Erlang/some other Erlang VM language. I think Erlang is extremely cool and I've enjoyed the little time I spent with Elixir. I also have absolutely no use case to make proper use of it.
I've been using niri lately and couldn't believe so many apps wouldn't launch. I didn't know that was the issue. I had been manually editing so many desktop entries to make them work...
Niri looks really cool. I've used tiling WM before but scrolling is a unique take, perhaps more productive for some folks?
Nushell is a good one. I do data science for a living and it'd be nice to have the shell handle some small data transformations instead of writing a script in python. But all the syntax and behavior is very different than bash, so I've been afraid to start because of the learning curve.
Ceph. I have some Raspberry Pi's that I'm going to set up a cluster with. Just haven't gotten around to it yet. I half expect the performance to be relatively terrible, but maybe it won't and I can try to build something on top of the cluster in a sort of hyper converged setup.
It's completely overkill for a small home lab but that's what makes it fun.
Mainly Firefox. It has quite a good extensions engine, but the overall UX just still isn't there compared to other browsers. I really don't care about all the ethical or moral reasons people try to come up with for using it, I just want a browser that has a lot of good functionality in comparison with Edge or Vivaldi.
And while I am aware of some of the forks like Floorp and Librewolf, I find the latter to be too hardened, and the former to be behind compared to upstream.