Varnish

Varnish Cache is a web accelerator also known as a caching HTTP reverse proxy. You can install it in front of any web server that speaks the HTTP protocol and configure it to cache the content. Varnish Cache is really, really fast and will boost the speed of your web site. One of the chief virtues of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which permits you to choose how incoming requests should be handled.

Memcached

Memcached is a general-purpose memory object caching system for boosting the load speed of dynamic database-driven websites. It is used to decrease 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 distributed memory caching system uses a client'server architecture. The Memcached memory caching system is employed by some of the most traffic-intensive sites on the World Wide Web and is supported by famous web applications like Joomla and WordPress.

Node.js

Node.js is a software platform for building scalable Internet apps. Written in JavaScript, Node.js uses an event-based, non-blocking input/output model that makes it lightweight and efficient, perfect for real-time content-rich apps. Node.js uses Google's V8 JavaScript engine, libUV, and a number of built-in libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source RDBMS. A storage engine is the main software component that a DBMS uses to create, retrieve, modify and delete data from a database. The latest release of InnoDB features considerable improvements in performance, reliability and usability. InnoDB offers the standard ACID-compliant database transaction attributes, as well as foreign key support. It is included by default in most binary distributions from MySQL AB.