Varnish

Varnish Cache is a web accelerator also called 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 contents. Varnish Cache is very, very fast and will improve your web site's speed. One of the major strengths of Varnish Cache is the flexibility of its configuration language, VCL, which allows you to determine how incoming requests should be dealt with.

Memcached

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

Node.js

Node.js is a software platform for building scalable network apps. Written in JavaScript, Node.js uses an event-driven, non-blocking input/output model that makes it lightweight and efficient, perfect for high-performance data-heavy 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 main software component that a database management system uses to create, read, modify and delete data from a database. The latest release of InnoDB features substantial improvements in performance, dependability and usability. InnoDB offers the standard ACID-compliant transaction features, along with declarative referential integrity support. It is included by default in most binaries distributed by MySQL AB.