The desktop app
A window around the panel, plus a native folder picker, first-run setup and update checking.
SpawnLoft runs on Windows, Apple Silicon and Intel Mac, and Linux. See downloads and platform support.
Appearance
Open Settings → Appearance to choose Classic, the original app palette, or SpawnLoft, inspired by the website.
Closing the window does not stop your servers
Servers are detached processes that do not belong to the app. Close the window, sign back in later, and they are still running with their consoles intact.
Terminal commands
Packages include spawnloft and mcctl launchers that use the bundled runtime, so no separate Node is needed. See CLI setup.
Updates
SpawnLoft checks for new releases after startup and every six hours while it is open. New versions download in the background. When one is ready, the header button reads Restart to update.
The app waits for you to restart before replacing the running version. Closing the app with an update waiting also applies it on exit. Running servers survive either way: only the app window restarts.
On Linux the update installs through a system password prompt. To follow the betas between releases, turn on Settings → Updates → Get beta builds; see automatic updates and beta builds.
Signed builds and SmartScreen
Windows production releases are signed under a validated publisher identity, which is what turns "Unknown publisher" into a name in the install prompt.
Mac builds are Developer ID signed with hardened runtime, Apple notarization and a stapled ticket. Download the DMG matching your Mac architecture.
It does not make SmartScreen go away immediately. SmartScreen is a reputation system, not a signature check, and reputation accrues through real installs, so a new publisher still gets warned about. More info → Run anyway is the way past it until the reputation builds.
Uninstalling
The uninstaller removes the program and asks one question: whether to delete your servers, worlds, backups, downloaded jars and settings too. The default is no, so uninstalling to reinstall loses nothing. Either way it first stops every running server and removes every scheduled task, since a task left behind would keep firing at a program that is gone. An update never does any of this.
Choosing yes deletes only what SpawnLoft created. A server you added from an existing folder stays where it is, and a data folder shared with other files loses only SpawnLoft's own folders. The terminal equivalent is spawnloft uninstall --yes [--data].
Which build you have
Settings → About names the version and the exact commit the build came from, so a bug report can name a build rather than a version several builds could share.
Where things live
The data folder holds the registry of servers, the servers SpawnLoft created, the jar store, backups and per-server runtime state. Settings can move it. Servers you added from a folder you already had keep living wherever they are; only their runtime state lands in the data folder.