Varnish

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

Memcached

Memcached is a generic memory caching system for boosting the speed of dynamic database-driven websites. 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 memory caching system uses a client'server architecture. The Memcached distributed memory caching system is used by some of the most traffic-heavy sites on the 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, asynchronous input/output model that makes it lightweight and efficient, suitable for real-time data-rich network applications. Node.js uses Google's V8 JavaScript engine, libUV, and several in-built libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source relational database management system. A storage engine is the principal software component that a DBMS uses to create, read, update and delete data from a database. Its latest edition features significant improvements in efficiency, reliability and usability. InnoDB offers the standard ACID-compliant database transaction features, as well as foreign key support. It is included as standard in most binaries distributed by MySQL AB.