Varnish

Varnish Cache is a web accelerator also known as an HTTP accelerator. You can install it in front of any server that speaks the HTTP protocol and configure it to cache the content. Varnish Cache is very, very fast and will improve your web site's loading speed. One of the chief pluses of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which enables you to define how incoming requests should be handled.

Memcached

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

Node.js

Node.js is a software system for writing highly scalable Internet apps. Written in JavaScript, Node.js uses an event-driven, asynchronous input/output model that makes it lightweight and efficient, perfect for real-time content-rich applications. 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 relational database management system. A database engine is the principal software component that a DBMS uses to create, read, update and delete data from a database. Its latest version features significant improvements in efficacy, security and usability. InnoDB offers the standard ACID database transaction features, as well as referential integrity support. InnoDB is included as standard in most binary distributions from MySQL AB.