Varnish

Varnish Cache is a web application accelerator also referred to as a caching HTTP reverse proxy. You can install it in front of any server that speaks HTTP and configure it to cache the content. Varnish Cache is very, very fast and will improve your site's loading speed. One of the important strengths of Varnish Cache is the flexibility of its configuration language, VCL, which enables you to define how incoming requests should be handled.

Memcached

Memcached is a general-purpose distributed memory object caching system for increasing the speed of dynamic database-powered websites. It is used to decrease 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 memory caching system uses a client'server architecture. The Memcached memory object caching system is employed by some of the most popular web sites on the World Wide Web and is supported by famous web apps like Joomla and WordPress.

Node.js

Node.js is a platform for writing highly scalable network apps. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, asynchronous input/output model that makes it lightweight and efficient, perfect for high-performance content-rich applications. Node.js uses Google's V8 JavaScript engine, libUV, and a number of built-in libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source relational database management system. A storage engine is the underlying software component that a database management system uses to create, retrieve, update and delete data from a database. The latest release of InnoDB offers serious improvements in efficacy, dependability and usability. InnoDB offers the standard ACID database transaction properties, along with referential integrity support. InnoDB is included as standard in most binaries distributed by MySQL AB.