Varnish

Varnish Cache is a web 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 contents. Varnish Cache is really, really fast and will improve your website's speed. One of the major merits of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which enables you to choose how incoming requests should be dealt with.

Memcached

Memcached is a general-purpose memory caching system for increasing the load speed of dynamic database-powered websites. It is used to decrease 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 popular websites 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 applications. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, asynchronous input/output model that makes it lightweight and effective, ideal for high-performance data-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 DBMS. A database engine is the primary software component that a DBMS uses to create, retrieve, update and delete data from a database. The latest release of InnoDB features considerable improvements in performance, reliability and usability. InnoDB provides the standard ACID-compliant transaction properties, as well as foreign key support. InnoDB is included as standard in most binary distributions from MySQL AB.