Varnish

Varnish Cache is a web application accelerator also called as a caching HTTP reverse proxy. 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 loading speed of your website. One of the main virtues of Varnish Cache is the flexibility of its configuration language, VCL, which permits you to determine how incoming requests should be tackled.

Memcached

Memcached is a general-purpose memory object caching system for speeding up 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 two-tier architecture. The Memcached system is used by some of the most traffic-intensive web sites on the Internet and is supported by popular web applications like Joomla and WordPress.

Node.js

Node.js is a platform for building highly scalable network apps. Built on Chrome's JavaScript runtime, Node.js uses an event-based, asynchronous I/O model that makes it lightweight and efficient, excellent for real-time data-intensive Internet applications. Node.js uses Google's V8 JavaScript engine, libUV, and a number of in-built libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source RDBMS. A database engine is the principal software component that a database management system uses to create, retrieve, update and delete data from a database. The latest release of InnoDB offers considerable improvements in efficiency, reliability and functionality. InnoDB offers the standard ACID transaction features, as well as foreign key support. InnoDB is included by default in most binaries distributed by MySQL AB.