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 the HTTP protocol and configure it to cache the contents. Varnish Cache is very, very fast and will boost your web site's speed. One of the major advantages of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which allows you to determine how incoming requests should be handled.

Memcached

Memcached is a generic memory caching system for increasing the load speed of dynamic database-powered websites. It is used to reduce 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 object caching system uses a client'server architecture. The Memcached distributed memory caching system is employed by some of the most frequently visited websites on the Internet and is supported by popular web applications like Joomla and WordPress.

Node.js

Node.js is a software system for building highly scalable network applications. Built on Chrome's JavaScript runtime, Node.js uses an event-based, non-blocking input/output model that makes it lightweight and effective, great for high-performance content-heavy Internet apps. Node.js uses Google's V8 JavaScript engine, libUV, and several in-built libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source database management system. A storage engine is the primary software component that a DBMS uses to create, retrieve, modify and delete data from a database. The latest version of InnoDB offers significant improvements in efficiency, reliability and functionality. InnoDB offers the standard ACID-compliant transaction properties, as well as foreign key support. InnoDB is included by default in most binaries distributed by MySQL AB.