Another contribution to Wikipedia.org. This is a "survey of surveys" covering a technique for building fault-tolerant systems. This paper's goal was mainly to compress the description of the technique and clarify several points, specifically regarding message ordering.
The State Machine Approach '08 [PDF]
Wikipedia.org: State Machine Replication
This article puts the Paxos Survey in a larger context. While Paxos solves an important facet of distributed computing, there are many additional details which require the attention of system developers.