What is the most interesting design pattern you've ever met?
design-patterns
Solution
Crash Only Software: http://www.usenix.org/events/hotos03/tech/full_papers/candea/candea_html/ Abstract
Crash-only programs crash safely and recover quickly. There is only one way to stop such software -- by crashing it -- and only one way to bring it up -- by initiating recovery. Crash-only systems are built from crash-only components, and the use of transparent component-level retries hides intra-system component crashes from end users. In this paper we advocate a crash-only design for Internet systems, showing that it can lead to more reliable, predictable code and faster, more effective recovery. We present ideas on how to build such crash-only Internet services, taking successful techniques to their logical extreme.
Problem
Most of us have already used the casual patterns such as MVC, strategy, etc. But there must be some unusual solutions to unusual problems, and I'd like to hear about it.