The plugin system allows other developers to interact with or override certain functions in GSP-Panel. With plugins you can bind to events or override the addon management system for individual games. In the future this will be expanded to game updates, backups, and queries.
This system also replaces our legacy hook system, any new events/hooks will be released under this system.
The release of this system includes the Spiget Addon Manager that allows Minecraft user's to install plugins directly from spiget.org. The code for this plugin is open and can be viewed by going to includes/plugins/spiget.