Varnish Cache

Varnish Cache is a powerful web application accelerator and caching HTTP reverse proxy. Installed in front of any HTTP-speaking server, it caches content to significantly speed up delivery, often by 300 to 1000 times depending on the architecture. Notably fast, Varnish is typically limited only by network speed, effortlessly delivering up to 20 Gbps on standard hardware.

Its flexibility lies in its configuration language, VCL (Varnish Configuration Language), which allows users to define policies for handling incoming requests. With VCL, users can specify content to serve, its source, and how requests or responses should be modified.