Varnish

Varnish Cache is a web application accelerator also referred to as an HTTP accelerator. 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 boost your website's speed. One of the key pluses of Varnish Cache is the flexibility of its domain-specific language, VCL, which permits you to determine how incoming requests should be handled.

Memcached

Memcached is a general-purpose distributed memory object caching system for speeding up 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 distributed memory caching system uses a client'server architecture. The Memcached memory caching system is used by some of the most popular web sites on the web and is supported by popular web applications like Joomla and WordPress.

Node.js

Node.js is a platform for building scalable network apps. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, asynchronous I/O model that makes it lightweight and effective, ideal for real-time content-intensive network 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 database management system. A storage engine is the principal software component that a database management system uses to create, read, modify and delete data from a database. Its latest version features serious improvements in performance, reliability and functionality. InnoDB offers the standard ACID database transaction properties, along with declarative referential integrity support. It is included by default in most binary distributions from MySQL AB.