GeoWebCache

Maps are often static. As most mapping clients render WMS (Web Map Service) data every time they are queried, this can result in unnecessary processing and increased wait times. GeoWebCache optimizes this experience by saving (caching) map images, or tiles, as they are requested, in effect acting as a proxy between client (such as OpenLayers or Google Maps) and server (such as GeoServer, or any WMS-compliant server). As new maps and tiles are requested, GeoWebCache intercepts these calls and returns pre-rendered tiles if stored, or calls the server to render new tiles as necessary. Thus, once tiles are stored, the speed of map rendering increases by many times, creating a much improved user experience.

Features

• Implements OGC services including Web Map Tiling Service (WMTS), Web Map Service-Caching (WMS-C), and Tiled Map Service (TMS).
• Java J2EE application, works with Jetty, Tomcat, WebLogic, WebSphere, JBoss.
• Ability to serve as a compliant WMS by recombining and resampling tiles to answer arbitrary image requests.
• Pre-seeding and seeding-on-demand capability.
• Native output to Google Maps (including Google Mobile), Google Earth super overlays (vector and raster), Bing Maps, and Yahoo Maps.
• Fine control over tile expiration by REST API or GeoRSS notification.
• Disk quotas with Least Frequently Used (LFU) and Least Recently Used (LRU) algorithms to manage disk space effectively.
• Handles WMS requests with time, elevation, alternate styles and filters.

More about GeoWebCache:
http://www.geowebcache.org/