Varnish

Varnish Cache is a web accelerator also famous as an HTTP accelerator. 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 increase your website's loading speed. One of the main pluses of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which enables you to define how incoming requests should be handled.

Memcached

Memcached is a general-purpose memory caching system for increasing the load speed of dynamic database-powered sites. 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 object caching system uses a client/server architecture. The Memcached distributed memory caching system is used by some of the most traffic-intensive websites on the Internet and is supported by popular web apps like Joomla and WordPress.

Node.js

Node.js is a software system for writing scalable Internet apps. Written in JavaScript, Node.js uses an event-based, non-blocking I/O model that makes it lightweight and efficient, ideal for real-time content-heavy applications. Node.js uses Google's V8 JavaScript engine, libUV, and several built-in libraries.

InnoDB

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