System Administration Guide
Appendix C, UNIX directories and special device files

The /opt directory

The /opt directory

The /opt directory contains the actual system software in a series of subdirectories known as ``software storage objects'' or SSOs. All system utilities in the root filesystem (such as /usr, /bin, and so on) are actually links to an SSO. /opt contains the shared files of SSOs that can be used by clients of a server system, while /var contains the non-shared files. See ``Software storage objects'' in the Networking Guide or the hierarchy(M) manual page for more information.