ICCCM

In computing, ICCCM (Inter-Client Communication Conventions Manual) is a standard for X Window System clients to interact on the same server. They were compiled by the MIT X Consortium in 1988. Version 1.0 was released in July 1989 and version 2.0 in early 1994.

X deliberately specifies "mechanisms, not policies". Thus, a specification for customer interoperability was needed. The ICCCM specifies selection mechanisms, copy and paste buffers, interaction with the window manager, session management, manipulation of shared resources, and characterization of device colors. Atoms

The conventions use a concept called Atom, which is a unique name consisting of octets similar to a string, although they are not always ASCII characters, which allows clients to communicate with each other.

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