Varnish

Varnish Cache is a web accelerator also called as an HTTP accelerator. You can install it in front of any web server that speaks HTTP and configure it to cache the content. Varnish Cache is really, really fast and will increase the loading speed of your website. One of the main strengths of Varnish Cache is the flexibility of its domain-specific language, VCL, which allows you to choose how incoming requests should be tackled.

Memcached

Memcached is a generic distributed memory object caching system for increasing the speed of dynamic database-driven sites. 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 caching system is employed by some of the most traffic-intensive web sites on the web and is supported by famous web apps like Joomla and WordPress.

Node.js

Node.js is a software system for writing highly scalable network apps. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, ideal for real-time data-rich apps. Node.js uses Google's V8 JavaScript engine, libUV, and several built-in libraries.

InnoDB

InnoDB is the default storage engine for the MySQL open-source database management system. A database engine is the main software component that a DBMS uses to create, read, update and delete data from a database. The latest release of InnoDB offers serious improvements in efficacy, reliability and functionality. InnoDB provides the standard ACID-compliant transaction properties, as well as declarative referential integrity support. InnoDB is included by default in most binaries distributed by MySQL AB.