Varnish

Varnish Cache is a web application accelerator also known as an HTTP accelerator. You can install it in front of any server that speaks HTTP and configure it to cache the contents. Varnish Cache is very, very fast and will increase the loading speed of your site. One of the important virtues 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 generic distributed memory object caching system for boosting the 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 system uses a client'server architecture. The Memcached system is employed by some of the most regularly visited web sites on the Internet and is supported by famous web apps like Joomla and WordPress.

Node.js

Node.js is a platform for writing highly scalable network apps. Built on Chrome's JavaScript runtime, Node.js uses an event-based, asynchronous input/output model that makes it lightweight and effective, perfect for real-time data-heavy Internet apps. 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 DBMS. A storage engine is the principal software component that a DBMS uses to create, retrieve, modify and delete data from a database. The latest version of InnoDB features significant improvements in efficacy, reliability and functionality. InnoDB offers the standard ACID-compliant database transaction attributes, as well as declarative referential integrity support. InnoDB is included as standard in most binary distributions from MySQL AB.