Varnish

Varnish Cache is a web accelerator also known as a caching HTTP reverse proxy. You can install it in front of any web server that speaks HTTP and configure it to cache the contents. Varnish Cache is very, very fast and will increase your web site's loading speed. One of the major features of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which allows you to define how incoming requests should be tackled.

Memcached

Memcached is a general-purpose distributed memory caching system for increasing the load speed of dynamic database-driven websites. It is used to lower the number of times an external data source (such as a database 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 object caching system is employed by some of the most traffic-intensive websites on the web and is supported by popular web applications like Joomla and WordPress.

Node.js

Node.js is a software system for writing scalable network applications. Written in JavaScript, Node.js uses an event-driven, asynchronous I/O model that makes it lightweight and efficient, excellent for real-time content-rich network apps. 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 relational database management system. A storage engine is the principal software component that a database management system uses to create, read, modify and delete data from a database. Its latest release features significant improvements in performance, reliability and functionality. InnoDB offers the standard ACID-compliant transaction attributes, as well as foreign key support. InnoDB is included as standard in most binary distributions from MySQL AB.