Varnish

Varnish Cache is a web application accelerator also popular as an HTTP accelerator. You can install it in front of any server that speaks HTTP and configure it to cache the content. Varnish Cache is very, very fast and will increase the loading speed of your site. One of the key pluses of Varnish Cache is the flexibility of its configuration language, VCL, which allows you to specify how incoming requests should be handled.

Memcached

Memcached is a general-purpose memory caching system for boosting the speed of dynamic database-driven sites. 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 object caching system uses a two-tier architecture. The Memcached distributed memory caching system is used by some of the most traffic-intensive websites on the web and is supported by popular web applications like Joomla and WordPress.

Node.js

Node.js is a platform for writing highly scalable network applications. Written in JavaScript, Node.js uses an event-driven, non-blocking input/output model that makes it lightweight and effective, perfect for real-time data-rich 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 RDBMS. A storage engine is the primary software component that a DBMS uses to create, read, modify and delete data from a database. The latest version of InnoDB features significant improvements in performance, stability and usability. InnoDB offers the standard ACID transaction attributes, as well as referential integrity support. It is included by default in most binaries distributed by MySQL AB.