%BOOK_ENTITIES; ]> The open-source reference implementation of Wayland protocol is split in two C libraries, libwayland-server and libwayland-client. Their main responsibility is to handle the Inter-process communication (IPC) with each other, therefore guaranteeing the protocol objects marshaling and messages synchronization. This Chapter describes in detail each library's methods and their helpers, aiming implementors who can use for building Wayland clients and servers; respectively at and .