Varnish

Varnish Cache is a web application accelerator also known as a caching HTTP reverse proxy. You can install it in front of any server that speaks HTTP and configure it to cache the contents. Varnish Cache is really, really fast and will improve your website's loading speed. One of the key advantages of Varnish Cache is the flexibility of its configuration language, VCL, which enables you to define how incoming requests should be tackled.

Memcached

Memcached is a general-purpose memory object caching system for increasing the loading speed of dynamic database-powered sites. It is used to lower 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 distributed memory object caching system is employed by some of the most traffic-hungry sites on the World Wide Web and is supported by popular web apps like Joomla and WordPress.

Node.js

Node.js is a software platform for building highly scalable network applications. Written in JavaScript, Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and effective, ideal for high-performance content-heavy network applications. Node.js uses Google's V8 JavaScript engine, libUV, and a number of in-built libraries.

InnoDB

InnoDB is the default storage engine for the MySQL open-source database management system. A storage engine is the underlying software component that a database management system uses to create, read, update and delete data from a database. The latest release of InnoDB offers significant improvements in efficacy, reliability and functionality. InnoDB offers the standard ACID database transaction properties, along with foreign key support. InnoDB is included as standard in most binaries distributed by MySQL AB.