Editing X.Org Server (section)

===IPC===
The X.Org Server, and any x-client, each run as distinct processes. On Unix/Linux, a process knows nothing about any other processes. For it to communicate with another process, it is completely and utterly reliant on the kernel to moderate the communication via available [[inter-process communication]] (IPC) mechanisms.
[[Unix domain socket]]s are used to communicate with processes running on the same machine. Special socket function calls are part of the System Call Interface. Although [[Network socket|Internet domain sockets]] can be used locally, Unix domain sockets are more efficient, since they do not have the [[Communications protocol|protocol]] overhead ([[checksum]]s, byte orders, etc.).

X.Org Server does not use [[D-Bus]].

Sockets are the most common interprocess communication (IPC) method between the processes of the X server and its various X clients. It provides the Application Programming Interface (API) for communication in the TCP/IP domain and also locally only in the UNIX domain. There are several other APIs described in the X Transport Interface, for instance TLI (Transport Layer Interface). Other options for IPC between for the X client-server, require X Window system extensions, for instance the [[MIT-SHM|MIT Shared Memory Extension (MIT-SHM)]].