EROS-OS.org
Extremely Reliable OS. Small, secure, real-time microkernel with orthogonal persistence: pull the plug and restart with never a problem. Related to, and working with, ERights.org on E programming language. [Open source, GPL]

KeyKOS
Persistent, pure capability, microkernel OS. EROS's famous predecessor.

The EROS Alternative
Shapiro interview in 'Open-Source Security' issue. Of open source OSs, most people think only Linux and OpenBSD. But another open-source OS's architecture may be more secure than either of them. [Information Security Magazine]

EROS: A Principle-Driven Operating System from the Ground Up
Abstract of article by Jonathan S. Shapiro, Norm Hardy; published by IEEE Computer Society. [IEEE Software]

Verifying Operating System Security
A confined program is one unable to leak information to an unauthorized party or modify unauthorized resources, an essential feature of any secure component based system. A proof of correctness of EROS architecture for confinement. [ResearchIndex]

EROS: A Fast Capability System
This capability-based OS for commodity processors uses a one level storage model; store persistence is transparent to applications. Surprisingly, performance of this very high security system matches normal OSs. [ResearchIndex]