Varnish

Varnish Cache is a web application accelerator also popular as an HTTP accelerator. You can install it in front of any web server that speaks HTTP and configure it to cache the contents. Varnish Cache is very, very fast and will boost your site's speed. One of the main virtues of Varnish Cache is the flexibility of its domain-specific language, VCL, which enables you to choose how incoming requests should be tackled.

Memcached

Memcached is a general-purpose memory object caching system for boosting the loading speed of dynamic database-powered 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 distributed memory object caching system uses a client'server architecture. The Memcached distributed memory caching system is used by some of the most popular sites on the Internet and is supported by popular web applications like Joomla and WordPress.

Node.js

Node.js is a platform for building highly scalable Internet apps. Written in JavaScript, Node.js uses an event-based, non-blocking I/O model that makes it lightweight and effective, great for real-time data-intensive network applications. 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 DBMS. A storage engine is the primary software component that a database management system uses to create, read, update and delete data from a database. The latest release of InnoDB offers considerable improvements in performance, stability and usability. InnoDB provides the standard ACID-compliant database transaction properties, along with declarative referential integrity support. It is included by default in most binaries distributed by MySQL AB.