GCache is a Python module that provides a generic cache class useful for speeding up any application where objects are referenced by keys. It uses object metadata to optimize hit-rates and freshness for fetches, and uses a "write-through" mechanism for writes and deletes. It can use "if-modified-since" fetches or rsync delta updates to refresh stale cached objects. GSource classes are provided for generating useful metadata from common sources (os.stat calls and MIME headers). A simple example urlCache is implemented that supports HTTP 1.1 (rfc2616) cache-control and expire headers to ensure freshness. Also included is an rfc2616 package useful for parsing HTTP 1.1 headers, and a PCache package implementing a persistant cache using a Python shelve.