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 very, very fast and will improve the loading speed of your website. One of the essential strengths of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which allows you to determine how incoming requests should be dealt with.

Memcached

Memcached is a general-purpose distributed memory object caching system for boosting the speed of dynamic database-driven websites. It is used to lower 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 object caching system is employed by some of the most frequently visited web sites on the web and is supported by popular CMSs like Joomla and WordPress.

Node.js

Node.js is a software platform for building highly scalable Internet apps. Built on Chrome's JavaScript runtime, Node.js uses an event-based, asynchronous I/O model that makes it lightweight and efficient, ideal for high-performance data-intensive applications. 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 database management system. A database engine is the principal software component that a database management system uses to create, retrieve, update and delete data from a database. The latest edition of InnoDB offers significant improvements in efficiency, dependability and functionality. InnoDB provides the standard ACID-compliant transaction attributes, as well as foreign key support. InnoDB is included by default in most binary distributions from MySQL AB.