Choosing server software
On first start the console shows this menu. Type a number (or a name such as paper) and press Enter:
Minecraft Java 1) Paper 2) Purpur 3) Fabric 4) Forge 5) NeoForge 6) Vanilla
Minecraft Proxy 7) Velocity 8) BungeeCord
Minecraft Bedrock 9) Bedrock Dedicated Server
Bots & Apps 10) Python 11) Node.js 12) Java (custom .jar)
Voice & Music 13) TeamSpeak 3 14) LavalinkMinecraft Java and Velocity then ask for a version (press Enter for the latest). Minecraft and Bedrock ask you to accept the EULA, and TeamSpeak asks you to accept its license.
Skipping the menu
Set Server Type (and Server Version) in the Startup tab before the first start. Handy when you create servers for other people.
Switching later
Change Server Type in the Startup tab and restart. On a menu-mode server, deleting eggactyl.conf brings the menu back. Either way your worlds and files are kept.
Changing the Minecraft version
Set Server Version to the new version and restart. Back up first: worlds can't be downgraded.
Bots and apps
For Python, Node.js and custom Java, upload your files (or set Git Repository in the Startup tab) and set Startup File if it isn't detected.
Bedrock Dedicated Server and TeamSpeak 3 only run on x86_64 nodes.