Varnish

Varnish Cache is a web application accelerator also popular as a caching HTTP reverse proxy. You can install it in front of any web server that speaks HTTP and configure it to cache the content. Varnish Cache is really, really fast and will improve your web site's speed. One of the main virtues of Varnish Cache is the flexibility of its configuration language, VCL, which allows you to define how incoming requests should be dealt with.

Memcached

Memcached is a generic distributed memory caching system for boosting the load speed of dynamic database-powered web sites. It is used to reduce 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 client'server architecture. The Memcached memory caching system is employed by some of the most traffic-intensive websites on the Internet and is supported by popular CMSs like Joomla and WordPress.

Node.js

Node.js is a platform for building scalable Internet applications. Written in JavaScript, Node.js uses an event-based, asynchronous I/O model that makes it lightweight and efficient, great for high-performance content-heavy Internet apps. 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 RDBMS. A storage engine is the primary software component that a database management system uses to create, read, update and delete data from a database. Its latest version offers significant improvements in efficiency, stability and usability. InnoDB offers the standard ACID-compliant transaction attributes, as well as referential integrity support. It is included by default in most binaries distributed by MySQL AB.