Varnish

Varnish Cache is a web application accelerator also referred to as a caching HTTP reverse proxy. You can install it in front of any web server that speaks the HTTP protocol and configure it to cache the content. Varnish Cache is really, really fast and will improve your web site's speed. One of the major attributes of Varnish Cache is the flexibility of its domain-specific language, VCL, which allows you to specify how incoming requests should be handled.

Memcached

Memcached is a general-purpose distributed memory caching system for increasing the loading speed of 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 memory object caching system uses a client'server architecture. The Memcached distributed memory caching system is used by some of the most frequently visited web sites on the World Wide Web and is supported by popular CMSs like Joomla and WordPress.

Node.js

Node.js is a platform for writing highly scalable Internet applications. Built on Chrome's JavaScript runtime, Node.js uses an event-based, non-blocking input/output model that makes it lightweight and efficient, excellent for real-time data-intensive network apps. 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 RDBMS. A database engine is the principal software component that a DBMS uses to create, read, modify and delete data from a database. The latest version of InnoDB offers significant improvements in efficiency, reliability and usability. InnoDB provides the standard ACID transaction properties, along with referential integrity support. InnoDB is included as standard in most binary distributions from MySQL AB.