An ad-hoc server in the context of PPSSPP (the open-source PSP emulator) refers to network features that emulate the PlayStation Portable’s ad-hoc multiplayer functionality. On real PSP hardware, ad-hoc mode allowed Direct Device-to-Device multiplayer (local wireless). PPSSPP can emulate ad-hoc networking so multiple emulator instances (or compatible clients) can connect and play multiplayer games that originally used PSP ad-hoc mode.