Varnish

Varnish Cache is a web accelerator also called as an HTTP accelerator. You can install it in front of any server that speaks HTTP and configure it to cache the contents. Varnish Cache is really, really fast and will improve the speed of your web site. One of the essential virtues of Varnish Cache is the flexibility of its domain-specific language, VCL, which enables you to determine how incoming requests should be tackled.

Memcached

Memcached is a general-purpose memory caching system for boosting the load speed of dynamic database-powered websites. 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 caching system uses a client'server architecture. The Memcached memory caching system is employed by some of the most traffic-heavy websites on the World Wide Web and is supported by popular web apps like Joomla and WordPress.

Node.js

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

InnoDB

InnoDB is the default database engine for the MySQL open-source RDBMS. A storage engine is the underlying software component that a database management system uses to create, read, update and delete data from a database. The latest edition of InnoDB features considerable improvements in efficiency, dependability and functionality. InnoDB offers the standard ACID transaction features, as well as declarative referential integrity support. It is included by default in most binaries distributed by MySQL AB.