Varnish

Varnish Cache is a web application accelerator also popular as a caching HTTP reverse proxy. You can install it in front of any web server that speaks the HTTP protocol and configure it to cache the contents. Varnish Cache is very, very fast and will improve your website's loading speed. One of the important pluses of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which permits you to determine how incoming requests should be handled.

Memcached

Memcached is a generic distributed memory object caching system for speeding up dynamic database-powered sites. It is used to lower the number of times an external data source (such as a DB or API) is read by caching data and objects in RAM. The Memcached distributed memory object caching system uses a client/server architecture. The Memcached memory caching system is used by some of the most traffic-intensive sites on the web and is supported by popular web apps like Joomla and WordPress.

Node.js

Node.js is a software platform for writing highly scalable Internet applications. Built on Chrome's JavaScript runtime, Node.js uses an event-based, asynchronous input/output model that makes it lightweight and efficient, suitable for real-time content-intensive applications. Node.js uses Google's V8 JavaScript engine, libUV, and a number of in-built libraries.

InnoDB

InnoDB is the default storage engine for the MySQL open-source relational database management system. A storage engine is the main software component that a database management system uses to create, retrieve, update and delete data from a database. The latest edition of InnoDB offers substantial improvements in performance, dependability and functionality. InnoDB offers the standard ACID-compliant database transaction attributes, as well as referential integrity support. It is included as standard in most binary distributions from MySQL AB.