Rack::Cache is suitable as a quick drop-in component to enable HTTP caching for Rack-based applications that produce freshness (Expires, Cache-Control) and/or validation (Last-Modified, ETag) information. Standards-based (see RFC 2616 / Section 13). Freshness/expiration based caching Validation Vary support Portable: 100% Ruby / works with any Rack-enabled framework. Disk, memcached, and heap memo