The system of Instances for Interlude chronicles and many others, where is not implemented in gameplay, makes it possible to create unique instances for any events. For admins exists separated universe with name «GM Universe» from out of which they interact with any object from the world still hidden for him. This is not the unique system. Just was downgraded the retail function from higher chronicles and reworked for fixing all issues and extending functionality.
After reworking Geoengine in aCis project (Changeset 354) this system is not recommend for usage on the live servers without edition of Geoengine for supporting instances for doors (now any door is Geo object). For other L2J forks can be adapted without any problems.
Price: 15 € (w/o GeoEngine fix for aCis Rev.354 and above).
Price: 45 € (with GeoEngine fix for aCis Rev.354 and above). Want the cheap then contact to Hasha for fix.