wp-multisite

Use when building or adapting a WordPress plugin for Multisite/Network — network activation (register_activation_hook with $network_wide), network admin pages (network_admin_menu), per-site vs network-wide options (get_option / get_network_option / update_network_option), looping sites with get_sites() + switch_to_blog() / restore_current_blog(), super admin capabilities (is_super_admin(), manage_network,…