Minecraft Java, starting with Paper
What the first pilot supports, and what's explicitly out of scope.
The first pilot is scoped to Java Edition servers using Paper. You and your players need Minecraft Java Edition. Bedrock, cross-play, Forge/Fabric modpacks, and Discord bots are outside this first pilot.
Paper is a Minecraft Java server implementation with plugin support. Compatibility depends on the exact Minecraft and plugin versions. Share any must-have plugins in your request; support is not guaranteed.