1. A method, comprising: in a multi-virtual machine system in which virtual machines within said system each have local memory for private use and a shared memory for shared use amongst said virtual machines, performing the following: configuring management of a region of a cache by identifying an eviction sorting policy from amongst a plurality of available eviction sorting policies, said eviction sorting policy for an eviction policy plug-in that includes including program code to implement an eviction timing method, said eviction timing method to trigger eviction of an object from said region of cache, said sorting component including program code to implement a sorting method that implements said sorting policy, said sorting method to identify an object that is eligible for eviction in said region of cache, said configuring also including selecting a storage plug-in from amongst a plurality of storage plug-ins, said storage plug-in designed to access a virtual machine's local memory but not said shared memory, said region of cache being within said virtual machine's local memory but not said shared memory, said object used by an application that is processed on said virtual machine and that places a hard reference to said object in said cache region, said object not shareable with other virtual machine within said system; and managing said region of cache by executing said eviction timing method and said sorting method from said plug-in, said executing of said eviction timing method including indicating an object is to be evicted from cache in response to another object being newly entered into said region of cache, said executing of said eviction sorting method including: identifying an object that has been cached in said region of cache for a longer time period than other objects that are cached in said cache region, wherein said identifying causes said eviction policy plug-in to evict said object from said cache region despite the presence of said hard reference; and evicting an entire shared closure from said shared memory if the identified said object is a member of said shared closure, wherein said shared closure is a group of one or more objects where every reference stemming from said object in said group does not reference an object outside that said group.