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 the HTTP protocol and configure it to cache the content. Varnish Cache is very, very fast and will increase your website's speed. One of the key pluses of Varnish Cache is the flexibility of its configuration language, VCL, which enables you to determine how incoming requests should be dealt with.

Memcached

Memcached is a generic memory caching system for increasing the speed of dynamic database-powered websites. 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 caching system uses a two-tier architecture. The Memcached memory object caching system is used by some of the most traffic-hungry web sites on the World Wide Web and is supported by famous web apps like Joomla and WordPress.

Node.js

Node.js is a platform for building scalable network apps. Written in JavaScript, Node.js uses an event-based, non-blocking I/O model that makes it lightweight and effective, perfect for real-time data-rich network applications. 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 RDBMS. A storage engine is the principal software component that a database management system uses to create, retrieve, update and delete data from a database. The latest version of InnoDB features serious improvements in efficiency, stability and functionality. InnoDB provides the standard ACID database transaction properties, along with foreign key support. InnoDB is included by default in most binary distributions from MySQL AB.