For those interested in emulators rather than leaked retail files, the hsreina/pangya-server project provides an open-source server emulator.
Offers a step-by-step setup for Season 8 files. pangya offline server link
Often hosts updated lists of currently active private servers and archival links for those wanting to host their own. Setting Up Your Own Offline Server For those interested in emulators rather than leaked
This is the primary hub for server development. You can find "Quick offline server guides" and file repacks for various seasons. pangya offline server link