Makes your server appear offline in server listings, and act like it's offline if you have a whitelist and someone not on it tries to join.
Currently works against clients running 1.6 and up. Older clients will still detect the server as online, but this is being worked on.
Using ProtocolLib, OfflineServer intercepts server list info packets and makes sure they are never processed by the server. This way the server appears to be offline, but in reality it's actually online.
This application uses open source components. You can find the source code of their open source projects along with license information below.
Project: Kotlin https://github.com/JetBrains/kotlin
Copyright (c) 2020, JetBrains
License (Apache License v2.0) https://github.com/JetBrains/kotlin/blob/master/license/LICENSE.txt
Project: Spigot-API https://hub.spigotmc.org/stash/projects/SPIGOT
Copyright (c) 2019, md_5
License (GNU General Public License v3.0) https://github.com/SpigotMC/Spigot-API/blob/master/LICENCE.txt
Project: ProtocolLib https://github.com/dmulloy2/ProtocolLib/
Copyright (c) 2019, dmulloy2
License (GNU General Public License v2.0) https://github.com/dmulloy2/ProtocolLib/blob/master/License.txt