You are looking for a file named minecraft_server.1.8.1.jar or minecraft_server.1.8.1.exe .

You can customize your world by editing the server.properties file with a text editor:

Open Minecraft 1.8.1, go to Multiplayer, and add a server with the address localhost .

Double-click it. It will generate several files and then close automatically.

Move the downloaded .jar or .exe file into your dedicated folder.

If you want plugins, you might consider Bukkit or Spigot 1.8.1. 3. Initial Setup & EULA