Varnish

Varnish Cache is a web application 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 boost the speed of your website. One of the major advantages of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which allows you to specify how incoming requests should be tackled.

Memcached

Memcached is a general-purpose memory object caching system for boosting the loading speed of dynamic database-driven web sites. 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 system uses a client'server architecture. The Memcached distributed memory caching system is employed by some of the most popular web sites on the Internet and is supported by popular 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 input/output model that makes it lightweight and efficient, suitable for real-time data-rich Internet applications. Node.js uses Google's V8 JavaScript engine, libUV, and a number of built-in libraries.

InnoDB

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