Varnish

Varnish Cache is a web application accelerator also known 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 contents. Varnish Cache is really, really fast and will increase your site's loading speed. One of the essential virtues of Varnish Cache is the flexibility of its domain-specific language, VCL, which allows you to choose how incoming requests should be handled.

Memcached

Memcached is a general-purpose distributed memory 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 system uses a client/server architecture. The Memcached memory caching system is used by some of the most frequently visited web sites on the World Wide Web and is supported by famous CMSs 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 effective, ideal for high-performance data-heavy 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 RDBMS. A database engine is the main software component that a database management system uses to create, retrieve, update and delete data from a database. The latest edition of InnoDB offers considerable improvements in efficacy, reliability and usability. InnoDB provides the standard ACID-compliant database transaction properties, along with foreign key support. It is included by default in most binary distributions from MySQL AB.