Varnish

Varnish Cache is a web application accelerator also referred to as a caching HTTP reverse proxy. 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 boost your site's loading speed. One of the key virtues of Varnish Cache is the flexibility of its domain-specific language, VCL, which permits you to specify how incoming requests should be handled.

Memcached

Memcached is a generic memory object caching system for speeding up dynamic database-driven websites. It is used to decrease 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 memory caching system uses a two-tier architecture. The Memcached memory caching system is used by some of the most traffic-hungry sites on the World Wide Web and is supported by famous CMSs like Joomla and WordPress.

Node.js

Node.js is a platform for building scalable network applications. Built on Chrome's JavaScript runtime, Node.js uses an event-based, non-blocking input/output model that makes it lightweight and efficient, ideal for high-performance content-heavy apps. Node.js uses Google's V8 JavaScript engine, libUV, and several built-in libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source relational database management system. A database engine is the primary software component that a DBMS uses to create, retrieve, update and delete data from a database. The latest version of InnoDB features substantial improvements in efficiency, dependability and usability. InnoDB offers the standard ACID database transaction properties, along with referential integrity support. InnoDB is included by default in most binary distributions from MySQL AB.