Varnish

Varnish Cache is a web accelerator also called 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 content. Varnish Cache is really, really fast and will improve your website's loading speed. One of the key attributes of Varnish Cache is the flexibility of its domain-specific language, VCL, which enables you to determine how incoming requests should be tackled.

Memcached

Memcached is a general-purpose memory object caching system for boosting the load speed of dynamic database-powered websites. It is used to reduce 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 caching system uses a client/server architecture. The Memcached memory caching system is used by some of the most regularly visited sites on the Internet and is supported by famous web applications like Joomla and WordPress.

Node.js

Node.js is a platform for writing highly scalable network applications. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, asynchronous I/O model that makes it lightweight and effective, great for real-time data-rich network applications. Node.js uses Google's V8 JavaScript engine, libUV, and a number of in-built libraries.

InnoDB

InnoDB is the default storage engine for the MySQL open-source relational database management system. A storage engine is the primary software component that a DBMS uses to create, read, update and delete data from a database. The latest version of InnoDB offers significant improvements in performance, reliability and functionality. InnoDB provides the standard ACID database transaction properties, as well as declarative referential integrity support. It is included as standard in most binary distributions from MySQL AB.