Password-Capabilities and the Walnut Kernel

Abstract

The Walnut kernel is a capability-based operating system kernel that was developed in the Department of Computer Science at Monash University during the 1990s. This kernel is heir to many of the ideas that were implemented in the PasswordCapability System. Focusing on the programmer’s view, this paper describes the password-capability model and the features of theWalnut kernel and the design decisions taken in creating it. An ANSI compliant standard I/O library is used as an example of the expressive power of the system.