Varnish

Varnish Cache is a web accelerator also called as an HTTP accelerator. You can install it in front of any server that speaks the HTTP protocol and configure it to cache the content. Varnish Cache is very, very fast and will improve the speed of your web site. One of the major pluses of Varnish Cache is the flexibility of its configuration language, VCL, which enables you to choose how incoming requests should be dealt with.

Memcached

Memcached is a generic memory object caching system for increasing 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 object caching system uses a client'server architecture. The Memcached memory caching system is used by some of the most traffic-hungry websites on the web and is supported by famous web apps like Joomla and WordPress.

Node.js

Node.js is a software platform for writing highly scalable Internet applications. Built on Chrome's JavaScript runtime, Node.js uses an event-based, asynchronous I/O model that makes it lightweight and efficient, ideal for high-performance content-rich Internet applications. Node.js uses Google's V8 JavaScript engine, libUV, and several in-built libraries.

InnoDB

InnoDB is the default storage engine for the MySQL open-source DBMS. A storage engine is the principal software component that a DBMS uses to create, retrieve, modify and delete data from a database. The latest release of InnoDB offers serious improvements in efficiency, security and usability. InnoDB offers the standard ACID transaction properties, as well as declarative referential integrity support. It is included by default in most binary distributions from MySQL AB.