Spigot
A modified Minecraft Java server based on CraftBukkit that runs Bukkit plugins and adds its own performance settings.
Spigot is a server software for Minecraft Java Edition. It is based on CraftBukkit, the server that implemented the Bukkit plugin API, and extends it with performance options and its own API additions. Spigot is developed by the SpigotMC community, which also runs one of the largest plugin resource sites and created the BungeeCord proxy.
BuildTools
The Spigot team does not distribute a ready-made server jar. Following a legal dispute around CraftBukkit in 2014, you build the jar yourself with a tool called BuildTools, which downloads the vanilla server and applies the patches locally. Many hosts and panels do this step for you.
Why it matters for server owners
Spigot defines much of the plugin ecosystem. Many plugins list “Spigot” as their platform, and its settings file spigot.yml controls things like entity activation ranges, item merge radius and the bungeecord switch for running behind a proxy.
Today most plugin servers use Paper instead. Paper is a fork of Spigot, reads the same spigot.yml, runs the same plugins and adds further performance work. There are few reasons left to choose plain Spigot for a new server, but understanding it helps when plugin pages or tutorials refer to it.
Practical tip
If a plugin lists Spigot in its requirements, it will almost always run on Paper as well. The reverse is not true: plugins built specifically against Paper’s API will not load on Spigot. When in doubt, check the plugin page for supported platforms and the Minecraft version it was built for.