An operating system security or access control model where specifIC types of access to a specifIC object are granted by giving a process this data structure or token. The token may be unforgeable (typICally by using encryption or hardware "tagged" memory). Capabilities are used in OSes such as Hydra, KeyKOS, EROS, Chorus/Mix, and the Stanford V system. Similar to Kerberos, but in an OS context. Compare access control list. (1998-03-08)