resoundingly yes.

XMPP server, do some decentralised communication under your control. It will federate to other servers, allowing you to speak to other people and join public chats. An old Raspberry Pi should easily be able to server 100 or 200 users. Try Prosody for that or Snikket if you prefer containers and everything working out of the box.

You could also use it as a NAS, if you don’t need a fast NAS. It will probably be enough to stream HD media using VLC on a cheap Android TV device/dongle.

I have an entire home server running on my pi; it’s just going to depend on what model you have and what you want to do with it. Personally, I run my pi from an SSD kept in a USB drive enclosure because microSD cards suck and I want my system to be responsive. I host websites and ssh into it all the time for a great number of random tasks. I have a custom Fedora install, but Raspberry Pi OS or whatever they switched the name to after Raspbian is probably fine for most people. It’s based on Debian, or at least is was many years ago when I last saw anything about it.

Raspberry Pi’s are full of possibilities, even old ones. Here is what I’d do.

It was supposed to be a pi-hole but was never able to get the dns forwarding to work on my modem.

Not sure what you mean here but there is no reason that any modem or WAN box ever really needs to involved with a pi-hole. You can set the IP to use for DNS lookups on each host by hand… OR you can turn off DHCP services on the modem run that off of the PI, which then sends the IP of the PI/PiHole for DNS as part of the DHCP lease to each client.

At any rate, ideas for it:

• PiHole with encrypted DNS service out to the internet and past your ISP’s snooping modem.
• a Wireguard VPN server. This would allow for things like your phone to tunnel home use your fancy pi-hole to block all ads on your phone, privately. You’d also then have access to anything else hosted on your home network like Music/Movies/etc. Setup a samba share for that stuff somewhere. This raspberry pi can also pass your VPN client traffic back out to the internet if you setup (ip forwarding)[https://rob-ferguson.me/how-to-use-your-rpi-as-a-router/]. It’s an old pi, so it won’t be faster than 100Mbps, but for a phone/tablet that is likely fine.
• as a motion-activated camera or some other temperature monitoring box. You can setup a cronjob to archive the videos or send the collected temp readings to some database backend and use Grafana for a visualization front-end.
• setup a netflow collector/forwarder for your LAN using fprobe. If you network is flat and I guessing that it is, as long as you have a single network switch for both your wired and wireless clients (and a single subnet aka 192.168.0.x for all) then you can monitor the whole broadcast domain with one box. You can send/forward the captured netflow to something like Security Onion and really start to understand what’s happening on your network. : )

There are so many more ideas like weather stations, news feeds, little web services for whatever.

As desktop? Barely. But you can overclock. Terminal stuff is fine.

If you want to tinker with a terminal it should do it just fine.

The Pi Hole part is still possible, though. If it is a crappy ISP router then it into a gateway and grab a cheap router on marketplace to do the real work.

Actually, if you are just planning to figure out the basics and not do heavy lifting with it, it would do both just fine. You could learn a bit by getting it configured and keeping it up.

You need an sd card adapter that lets you read and write the sd card from your pc to put an image the pi can boot onto the sd card.

You will need this anyway when you eventually run into the sd card having a bunch of of bad blocks or unreadable sectors.

It will work ”fine” for what you’re describing but consider getting one of those sata/m2 adapter boards so your root filesystem isn’t based on the media explicitly designed for temporarily holding information until the user can get back to a computer.

If you already have a computer, just set up a vm.

If you need to reimage it, it sounds like you’re looking for “Headless Rasbian”. As others have said, it is based on Debian.

A lot of stuff I want to learn/practice “work” on windows but are native to Linux, like vim/neovim nmap gcc etc. Is this feasible?

Absolutely. And it’s fun.

Am I under estimating what’s possible with it?

Haha. Yeah. I read somewhere that the Pi3 is the most capable budget PC ever produced, and I have no reason to doubt that claim.

But you can always do more with it later. May as well start with trying what you’re interested in now.

Raspberry Pi OS is based on Debian. You should be able to do what you’re describing and more by enabling SSH even without changing the OS.

Assuming it’s a Pi 3, Wireguard will work on it, as will Syncthing (useful if you add an SSD) but the interface bandwidth is limited so it can be a bit slow. That may not be too much of a problem though. My cable Internet’s upload speed is limited to 20Mbps, and despite the limited bandwidth both Wireguard and Syncthing are surprisingly useful.

I helped set up many households with kids on Pi-2s and 3s, running Raspbian and Kano. All you needed was a keyboard, mouse, and a monitor. It all worked fine with Scratch, Minecraft, LibreOffice, Web, and email.

At least, until the kids outgrew them.

My 2b+ is still chugging along running my webserver, hosting some scripts run by CRON, and a badly configured pi-hole. No complaints!

You have the pi. Install Linux and find out? It takes like 10 mins… Otherwise it really depends on what you want to do and your expectations.

I’ve got a raspberry pi 1 (didn’t even have on-board wifi) that I just fired up the other day. It’s pretty slow but if you just wanted to do some simple python development it might be fine (depending on your patience for installing dependencies).

Yes you can do loads with your Raspberry Pi. Certainly you can install ARM based linux distros onto it, but with an older model you’re best using a Pi specific linux distro.

The official Raspberry Pi OS is linux and is compatible with all Raspberry Pi models - there is a universal 32bit version and a 64bit version for newer models 3+.

There is also Dietpi which tries to be more lightweight and optimised.

You can image either distro onto an SD card and run it on the Pi. If you connect the pi to your network you can run it headless and access it via SSH on your PC.

However, if you main aim is to learn and play with Linux, then it is worth considering alternatives. For example, you could install VirtualBox on your Windows PC, and create a virtual PC to run any X86 linux distro you’d like on it. That can include small systems with command line only or a full desktop environment of your choice. That would likely give you much higher performance and options than a 10 year old raspberry pi can offer.

The Pi is good if you want an always on server device to play with Linux on. The Virtual machine route is good if you want a more powerful system to play with occasionally when you feel like it.