Tauon is my favorite music player. Don’t hear about it much. Handles large libraries really well. Pretty sure it will play DSD too. https://github.com/Taiko2k/Tauon or https://flathub.org/apps/com.github.taiko2k.tauonmb

Laptop is foss except bios. Desktop has apu and wifi firmware.

Open source, more modern, Ultima Online client. Still need the original art files. https://github.com/ClassicUO/ClassicUO

DOS, ProDOS, Windows 3.1, Windows '98, Windows 2000, Windows XP, Windows 7, Puppy, Mint, Bodhi, Trisquel & Debian.

ClassicUO is a nice open source client for Ultima Online. Need to have the game assets.