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 content. Varnish Cache is really, really fast and will increase your site's speed. One of the important virtues of Varnish Cache is the flexibility of its configuration language, VCL, which enables you to define how incoming requests should be dealt with.

Memcached

Memcached is a generic memory caching system for boosting the speed of dynamic database-powered web sites. It is used to decrease 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 two-tier architecture. The Memcached system is used by some of the most frequently visited sites on the Internet and is supported by famous web applications like Joomla and WordPress.

Node.js

Node.js is a software platform for building scalable Internet applications. Written in JavaScript, Node.js uses an event-driven, asynchronous I/O model that makes it lightweight and effective, ideal for real-time content-intensive Internet applications. Node.js uses Google's V8 JavaScript engine, libUV, and a number of in-built libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source relational database management system. A database engine is the underlying software component that a DBMS uses to create, read, modify and delete data from a database. Its latest release features substantial improvements in efficacy, dependability and functionality. InnoDB offers the standard ACID database transaction attributes, as well as declarative referential integrity support. InnoDB is included as standard in most binary distributions from MySQL AB.