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 contents. Varnish Cache is really, really fast and will boost your web site's speed. One of the chief virtues of Varnish Cache is the flexibility of its configuration language, VCL, which enables you to determine how incoming requests should be handled.

Memcached

Memcached is a general-purpose distributed 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 DB or API) is read by caching data and objects in RAM. The Memcached distributed memory caching system uses a two-tier architecture. The Memcached distributed memory object caching system is employed by some of the most popular web sites on the World Wide Web and is supported by popular Content Management Systems like Joomla and WordPress.

Node.js

Node.js is a software platform for building highly scalable Internet apps. Written in JavaScript, Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, great for real-time content-rich network apps. Node.js uses Google's V8 JavaScript engine, libUV, and several in-built libraries.

InnoDB

InnoDB is the default storage engine for the MySQL open-source RDBMS. A storage engine is the primary software component that a DBMS uses to create, retrieve, update and delete data from a database. Its latest release offers significant improvements in performance, security and functionality. InnoDB offers the standard ACID-compliant database transaction attributes, along with declarative referential integrity support. InnoDB is included by default in most binary distributions from MySQL AB.