Inter-Client Communication Conventions Manual
（重定向自ICCCM）
In computing, the Inter-Client Communication Conventions Manual (ICCCM or I39L short for "I", 39 letters and "L") is a standard for interoperability between X Window System clients of the same X server. It is primarily used for communication between normal clients and the window manager. It was designed by David S. H. Rosenthal of the MIT X Consortium in 1988. Version 1.0 was released in July 1989 and version 2.0 in early 1994.