Varnish

Redis Object Cache is a WordPress plugin that provides persistent object caching using Redis. It replaces the default WordPress object cache with a Redis-backed solution, significantly improving performance for database-driven websites. The plugin offers features like automatic caching of database queries, transients, and object cache groups. Its ability to reduce database load and improve response times, especially for high-traffic WordPress sites, makes it popular among developers and site owners looking for advanced caching solutions. The use of Redis as a backend ensures fast, in-memory data storage and retrieval.

Oracle Web Cache is a browser and content management server, which improves the performance of web sites.

RackCache is a quick drop-in component to enable HTTP caching for Rack-based applications. It provides a simple way to add caching capabilities to Ruby web applications, improving performance by reducing the load on application servers. RackCache offers features like support for various cache stores, automatic cache expiration, and configurable caching policies. Its lightweight nature and easy integration with Rack middleware make it popular among Ruby developers looking to implement efficient caching in their web applications without significant code changes.