Some options for machines that can be used to self-host a Nostr app: Raspberry Pi - Low-cost, small single board computers - Models like Raspberry Pi 4 have enough CPU and RAM to run Nostr clients - Easy to set up, portable, low energy usage Linux VPS - Virtual private servers running Linux - Providers like DigitalOcean, Linode, Vultr allow deploying custom Linux VMs - More flexibility and options for computing power and resources   Linux on a home media server - Old desktop or laptop hardware can be repurposed - Lightweight Linux distro like Ubuntu Server or Docker - Always-on convenience for self-hosting Linux development board (SBC) - Single board computers like Asus Tinker Board, ODROID, Rock64 - Power efficient with GPIO, networking and USB capabilities - Reasonable compute power for self-hosting On a NAS (Network Attached Storage) - Many DIY and consumer NAS devices run Linux - Can install Linux applications alongside storage functions - Built-in availability as network attached appliance The common requirements are ability to run a Linux or Unix environment and connectivity to the internet. More powerful hardware allows supporting increased users and workloads.