AppFabric Caching Service
AppFabric Caching Service is a distributed cache platform for in-memory caches spread across multiple systems, developed by Microsoft. It is one of Microsoft's AppFabric's Services. In its early stages of development, it was referred by a code name Velocity.
AppFabric Caching Service is available as a Windows Azure Service.
Design
Any number of systems can be a part of the cache; the caching runtime pulls together the individual caches on each machine to present a unified view to the applications. Applications need not know on which machine the cache is stored; rather the applications query the caching runtime which in turn forwards the request to the system that houses the cache item. The API is surfaced in managed code; so any CLI-compliant language can be used to access the cache. Any serialized managed object can be added to the cache.