Varnish

Varnish Cache is a web application accelerator also known as an HTTP accelerator. You can install it in front of any web server that speaks HTTP and configure it to cache the contents. Varnish Cache is really, really fast and will improve your site's loading speed. One of the main attributes of Varnish Cache is the flexibility of its domain-specific language, VCL, which allows you to determine how incoming requests should be dealt with.

Memcached

Memcached is a general-purpose memory caching system for boosting the loading speed of dynamic database-powered 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 memory caching system uses a two-tier architecture. The Memcached distributed memory object caching system is employed by some of the most traffic-hungry web sites on the World Wide Web and is supported by famous Content Management Systems like Joomla and WordPress.

Node.js

Node.js is a platform for building scalable network applications. Built on Chrome's JavaScript runtime, Node.js uses an event-based, asynchronous input/output model that makes it lightweight and effective, suitable for high-performance content-rich network applications. Node.js uses Google's V8 JavaScript engine, libUV, and a number of in-built libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source RDBMS. A storage engine is the underlying software component that a DBMS uses to create, retrieve, update and delete data from a database. Its latest version features serious improvements in efficiency, reliability and functionality. InnoDB offers the standard ACID transaction properties, along with declarative referential integrity support. InnoDB is included as standard in most binaries distributed by MySQL AB.