Mjolnir is a fault tolerance and isolation library that employs timeouts, bulkheads, and circuit breakers to make network and other dependency calls resilient against failure. It's modeled after Netflix's awesome Hystrix library. Some components are ports, but much of it has been written using C#- and .NET-specific features (e.g. async/await, CancellationTokens).
See the Wiki for more details and documentation.