Plex
★★★☆☆
On the plus side: It works, the players are easy to find and install for multiple platforms and devices, and the server can even run on a Raspberry Pi.
On the minus side: You have to sign into their cloud account to do most things. And it’s constantly trying to push you into purchasing a subscription. Even if you’re only using it with your local collection.
If you want to use it for remote streaming, that’s one thing. But I just want to listen to my own library of music on my own network. It shouldn’t have to connect to a remote service, sending who knows what local data, just for that. I ended up using Jellyfin instead.
(Oh, and installing on a Pi? You need to either hook up a display to it or use an ssh tunnel to complete setup if you’re trying to run it as a headless server.)
More info at Plex.